Fluxtrol

Consulting on Magnetic Flux Control

Mon, 01 Jan 0001 00:00:00 +0000

Induction heating is used as a heat source in a wide variety of applications. Oftentimes, applications of induction heating or ideas of where induction heating could be used are developed by people who are experts in the product or process rather than induction heating itself. In other cases, induction heating processes were developed by highly skilled individuals whom have since retired or moved on to another company without fully transferring their induction heating knowledge.

Fluxtrol A

Mon, 01 Jan 0001 00:00:00 +0000

Fluxtrol A has the highest maximum magnetic permeability and the lowest magnetic losses at low to intermediate frequencies in the Fluxtrol family of soft magnetic composites (favorable magnetic direction). Fluxtrol A also has good mechanical strength, thermal conductivity, and is readily machinable. However, it does have high magnetic and thermal anisotropy, which should be taken into account when using the product.

Fluxtrol Induction Technology

Mon, 01 Jan 0001 00:00:00 +0000

This chapter of the free Fluxtrol induction heating course walks through fluxtrol induction technology in 11 slides. View the slides below, or skim the outline and slide text.

Slide text

0. Introduction

Basics of Induction Technique and Magnetic Flux Control by. Dr. Valentin Nemkov

Course Contents

INTRODUCTION Ia.
BASIC OF INDUCTION TECHNIQUE -PART 1 Ib.
BASIC OF INDUCTION TECHNIQUE -PART 2 II.
INDUCTION INSTALLATIONS III.
INDUCTION COIL STYLES I V.
COMPUTER SIMULATION V.
MAGNETIC FLUX CONTROL VI.
APPLYING FLUXTROL TO INDUCTION COILS VII.
CASE STORIES VIII. HISTORICAL OVERVIEW GLOSSARY

Introduction

This Training Course is developed for people with different technical levels (technology users, designers, coil manufacturers, businessmen etc.) for better understanding of:
How induction heating works
Equipment used for induction heating applications
How to design optimal processes and induction coils using computer simulation
The benefits of using magnetic flux controllers (concentrators)
Proper material selection and fabrication
The application of Fluxtrol controllers to induction coils
What results have been achieved in selected applications (case stories) It is not possible to describe in a short course all the features and numerous applications of induction heating.
The main emphasis will be placed on the theory, understanding and practice of magnetic flux control in induction heating systems.

Considerations

Induction technique is a complicated method involving Electrical, Magnetic and Thermal phenomena
Heating intensity and temperature distribution depend upon many factors (frequency, part size and shape, material properties, operating conditions) and may vary during the process of heating
Magnetic Flux Controllers effect not only the induction coil performance but influence (improve) operation of the whole induction installation
Induction technique has its own language, which the user needs to know for adequate communication with customers – see Glossary See Glossary

History of Induction Heating

Induction heating is based on fundamental works within the field of Electromagnetism and on scientific and technical contributions of a number of individuals in USA,Russia, Germany, France and other countries.
Historical knowledge of induction heating allows the reader to see the role this unique technology has played within the industrial revolution and equipment development
Some ideas of this pioneering period (50-70 years ago) have been implemented in practice only recently due to a new level of industrial demand, development of advanced materials, machines and control systems
A short History Overview composed by Professor Alfred Muehlbauer (Hanover University, Germany)may be found in a separate file See Historical Overview

Specific Features of Induction Heating

Heat generation occurs inside the part
Heating is contactless
Method can provide very high power densities
Heating may be highly selective in the depth and along the surface
Any processing atmosphere (air, protective gas, vacuum)
Very high temperature may be created
Stand-by losses of equipment are very low
Fast start-up
Heating may be easily programmed and automated
No contamination of treated material may be provided (important for medical material, semiconductors etc.!)
No pollution of surrounding space

Advantages of Induction Heating

Short heating cycles and high production rates
Better metallurgical results due to fast and clean heating
Energy savings due to selectivity and high efficiency
Good control and repeatability
Minimal or no surface oxidation and decarburization
Lower distortions
Favorable for industrial environment (in-line heating, no pollution, “push button” performance)
Some processes may not be accomplished other than by induction

Major Applications of Induction Heating

HEATING TREATING FORMING & FORGING MELTING WELDING BRAZING & SOLDERING BONDING SHRINK-FITTING INDUCTIVELY COUPLED PLASMA CRYSTAL GROWTH

Latest Achievements in Induction

Heating Technique
Compact and efficient transistor power supplies with wide frequency range operation
Intelligent control and monitoring systems
Simultaneous dual frequency hardening
Robotic induction installations
Computer simulation technology and CAD of induction processes and coils
Magnetic flux control techniques and concentrator materials

Improved Coil & Process Efficiency

Mon, 01 Jan 0001 00:00:00 +0000

The efficiency of an induction heating coil is limited by how much of its current does useful work. In a bare coil, much of the current flows where it heats nothing. Soft magnetic composites (SMCs) correct that by controlling the magnetic flux, so the same power supply delivers more heat to the part, or the same heat takes less power.

Induction Heating for Automotive

Mon, 01 Jan 0001 00:00:00 +0000

Automotive production is the industry where Fluxtrol’s induction hardening work is best documented. Axles, crankshafts, wheel hubs and camshafts all rely on surface or case hardening, and each has a library paper or case history behind it. Fluxtrol’s legacy company text lists automotive first among the industries where its solutions are used, and says it serves companies such as GM and GKN.

Machining Soft Magnetic Composites

Mon, 01 Jan 0001 00:00:00 +0000

Fluxtrol materials are composites of metal powder and plastic binders, and their machinability falls between plastics and metals. Ferrotron 559H is closer to plastics, while Fluxtrol A and 100 are more like light metals, although more brittle. Different grades call for different technique to get the best results.

SMC Impeder Cores | Pipe & Tube Welding Impeder Cores

Mon, 01 Jan 0001 00:00:00 +0000

In high-frequency induction welding, the impeder decides how much of the generator’s power ends up at the weld. For decades it has been a ferrite core. Fluxtrol’s soft magnetic composite (SMC) impeder cores replace that ferrite with a material that does not saturate as early and does not fracture under thermal shock, and the published evidence now covers trials, simulation and an off-line validation method.

Fluxtrol 100

Mon, 01 Jan 0001 00:00:00 +0000

Fluxtrol 100 has the highest thermal conductivity, saturation flux density and flexural strength of the Fluxtrol family of materials. Fluxtrol 100 has similar magnetic properties in the favorable direction to Fluxtrol A, but with significantly less anisotrophy both thermally and magnetically. Fluxtrol 100 has good machinability when sharp tools and high spindle speeds are used.

Heat Treating & Melting Expertise

Mon, 01 Jan 0001 00:00:00 +0000

Heat treating of different details is a traditional area of Research at CIT. It includes analysis of coupled electromagnetic and thermal phenomena during induction heating of steels and other materials, methods of computer simulation, material properties required for simulation and development of new processes and their tests in laboratory. In recent years, we conducted a study of stress and Deformation evolution in processes of induction hardening of different parts in close cooperation with Dante Solutions. This study ranged from initial analysis of coupled electromagnetic, thermal, structural and mechanical phenomena in bodies of simple geometry to simulation of stress and deformation dynamics in the axle shafts throughout the whole process of manufacturing and service performance. Dana Corporation also participated in this study, the results of which were presented in several publications.

Induction Coil Design & Engineering

Mon, 01 Jan 0001 00:00:00 +0000

It has been said that it is easy to design an induction heating coil that doesn’t work at all, and very difficult to design an induction heating coil that works really well. Fluxtrol has a reputation for solving the most complex coil design challenges with overwhelming success.

Induction Heating for Tube & Pipe Manufacturing

Mon, 01 Jan 0001 00:00:00 +0000

Tube and pipe manufacturing is where Fluxtrol’s soft magnetic composites have the most published production evidence. In high-frequency induction welding, a flat strip is formed into a tube, an induction coil heats the edges, and rolls press them together to form a longitudinal weld seam. Induction heats directly in the metal, giving localized heat at high line speeds.

Induction Heating Technique Part 1

Mon, 01 Jan 0001 00:00:00 +0000

This chapter of the free Fluxtrol induction heating course walks through induction heating technique part 1 in 30 slides. View the slides below, or skim the outline and slide text.

Chapter outline

What is Induction Heating?
Eddy Current and Hysteresis Heating
Principles of Induction Heating
Principles of Induction Heating (cont.)
Magnetic Field Lines
Electromagnetic Processes in Induction Installation
Layout of Induction Circuit with Sensors
Power Flow in Induction Heating Installations
Theory of Induction Heating
Reference (Skin) Depth
Reference Depth (cont.)
Examples of Power Distribution in Cylindrical Bodies
Reference Depth for Different Materials and Frequencies
Power Absorbed by Workpiece
Power Transfer Factor for Plate and Cylinder
Power Transfer Factor for Tubes
Thin or Thick Part ?
Electromagnetic Effects in Induction Systems
Concentrator Effect
Proximity Effect in “Coil - Flat Body” System
End Effects in Cylindrical Induction System
End Effects in Cylindrical Induction System
End and Edge Effects in Induction Heating of Slabs
Power Density Map Demonstrating End Effects in
Power Density Map Demonstrating Edge Effects in
Power Density Map in Non-Magnetic Slab (3D Corner
Questions and Answers

Slide text

What is Induction Heating?

Induction Heating is a Contactless Heating Method of bodies, which absorb energy from an Alternating Magnetic Field, generated by Induction Coil (Inductor) There are two mechanisms of energy absorption:
generation of close-loop (eddy) currents inside the body which cause heating due to electrical resistance of the body material
hysteresis heating (for magnetic materials ONLY !) due to a friction of magnetic micro volumes (domains), which rotate following orientation of external magnetic field

Eddy Current and Hysteresis Heating

Eddy current heating occurs in all conductive materials (magnetic or non -magnetic steels, copper, aluminum, graphite, molten glass or oxide etc.) when they are placed in an alternating magnetic field. Eddy currents always flow in a closed loop (law of nature!) and for effective heating there must be a good path for current to flow in the part to be heated. For example, it is easy to heat a wire loop but almost impossible to heat a thin wire then the loop is open.

Maintaining Induction Coils with SMCs

Mon, 01 Jan 0001 00:00:00 +0000

In many applications Fluxtrol concentrators work longer than the copper they are attached to. When they do fail, the cause is usually one of three things, and each is preventable.

Why concentrators fail

Mechanical damage by the part or during coil installation. This is one of the main factors in coil and concentrator failure.
Material overheating, which leads to crumbling. Causes include insufficient coil cooling, improper design and manufacturing, or separation of the concentrator from the coil tubing when the glue cracks.
Electrical break, which trips the power supply protection or causes arcing and burning. Causes include improper coil design, wrong material selection (for example Fluxtrol 50 instead of Ferrotron 559H) and metallic particles accumulating on the coil surface.

What to check during maintenance

Each check below maps to one of the failure modes above.

Precise Heat Pattern Control

Mon, 01 Jan 0001 00:00:00 +0000

In induction heat treating, the heat pattern is the product. The case depth, the hardness zone and the transition zone all follow from where the coil puts its power. A pattern that misses a fillet or spills onto a shoulder means rejected parts or extra distortion, so pattern control matters as much as efficiency.

Principles of Induction Heat Treating

Mon, 01 Jan 0001 00:00:00 +0000

Induction heat treating in brief

Induction heat treating covers hardening, tempering and annealing. It needs simultaneous control of electromagnetic fields, current flow, time and temperature. The usual goal is to heat a specific area of a part, such as a bearing race, journal or tooth flank, quickly above its austenitizing temperature and quench it right away to reach the case depth and hardness profile the specification requires. This page covers the principles; Methods and Inductor Styles apply them.

Fluxtrol 50

Mon, 01 Jan 0001 00:00:00 +0000

Fluxtrol 50 provides excellent performance over a wide range of frequencies. The material has good mechanical strength, machinability and thermal conductivity.

Note: There are many variables involved in an induction process. In order to utilize the fullest potential of our product, you must help narrow down the parameters you are operating with. Each grade of Fluxtrol material has its own distinctive properties that are beneficial to a certain range of electrical and design parameters.

Heat Treating Methods: Single-Shot and Scanning

Mon, 01 Jan 0001 00:00:00 +0000

Two ways to harden: single shot and scanning

All induction heat treating processes can be classified by whether the coil moves relative to the part during heating (excluding rotation). In single-shot hardening it does not; in scanning it does. Choosing between them depends on part geometry, heat treatment specification, material, production rate and the equipment available. The ASM Handbook chapter by Fluxtrol authors describes the choice as part of the first questions in inductor design: will the part run on an existing machine or does a new one have to be built.

High-Frequency Tube & Seam Welding

Mon, 01 Jan 0001 00:00:00 +0000

Faster, more efficient high-frequency welding

High-frequency (HF) welding is how most steel tube and pipe is made: strip is formed into a round, an induction coil heats the open seam, and pressure rolls forge the edges together. The process is fast and continuous, but it is energy intensive, and the heating pattern at the weld seam depends on how well the magnetic field is controlled.

Induction Coil Prototyping & Validation

Mon, 01 Jan 0001 00:00:00 +0000

Fluxtrol’s laboratory has power supplies ranging from 500 W to 50 kW with frequencies from 3 to 2000 kHz, and a large array of magnetic and thermal measurement tools, including thermal imaging cameras which aid in the ability to produce and analyze part production in a real life environment. With the ability to create production mock-ups and run prototype parts, Fluxtrol’s lab can be a useful validation tool for design concepts and production parts.

Induction Heating Computer Simulation

Mon, 01 Jan 0001 00:00:00 +0000

Computer simulation or modelling is a powerful tool for analyzing induction heating systems. Fluxtrol extensively uses computer simulation for the development and optimization of induction heating coils and processes. As compared to many other companies who use computer simulation only once they have not achieved the desired results empirically, Fluxtrol begins nearly every project with computer simulation to ensure that the best possible solution is delivered to the customer.

Induction Heating for Packaging

Mon, 01 Jan 0001 00:00:00 +0000

Packaging is an industry where Fluxtrol’s involvement is documented in patents and in its R&D collaboration, rather than in published case studies. This page summarizes only what the sources support.

What is documented

Fluxtrol’s R&D description says its engineering groups conduct cooperative development of new processes with world-leading companies in food packaging, among other fields, and acknowledges a long-term collaboration with Tetra Pak. The legacy company text also names Tetra Pak among the companies Fluxtrol serves. The sources do not describe the specific work.

Induction Heating Technique Part 2

Mon, 01 Jan 0001 00:00:00 +0000

This chapter of the free Fluxtrol induction heating course walks through induction heating technique part 2 in 25 slides. View the slides below, or skim the outline and slide text.

Chapter outline

Introduction
Power, Time & Frequency Ranges
Modern Induction Power Supplies
Heating Time
Frequency Selection
Power Density Curves for Induction
Recommended Frequency for Different Case Depths
Temperature Evolution During an
Comparison of Temperature Evolution for Mass Heating
Temperature Color Map for Induction Hardening Process
Resistivity and Permeability Variation
Variation of Reference Depth
Typical Power Variation in Surface Hardening
Example of Power Variation in
Electrodynamic Forces
Time Variation of Electrodynamic
Melt Stirring by Electrodynamic Forces
Excessive Electrodynamic Forces
Electrodynamic Forces Summary
Electrodynamic Forces Summary (cont.)
Conclusions to Basics
Questions and Answers

Slide text

Introduction

Part 1 of Basics dealt mainly induction heating systems with electromagnetic phenomena in
Part 2 of Basics deals with heating effects, dynamics of temperature distribution and coil parameter variation in the process of heating as well as with electrodynamic forces created by magnetic field

Power, Time & Frequency Ranges

A combination of Power, Time & Frequency defines an “Induction Process” Typically heating of larger parts requires more power at low frequency and heating time is longer (or the process is continuous) Frequency Ranges:
Though there is no standard for frequency ranges in induction heating, it is a common understanding that:
Low Frequency
50/60 Hz to 3 kHz (melting, forging, deep hardening) Middle Frequency - 3 to 50 kHz (surface hardening, brazing, small forging, tempering, shrink fitting etc.) High Frequency
50 to 500 kHz (shallow hardening, brazing, soldering, HF welding etc.) Radio Frequency
above 500 kHz (packaging, crystal growth, low temperature plasma and other special technologies)

Modern Induction Power Supplies

Modern power supplies cover all industrial demand in power for a very wide range of frequencies.
If necessary, several power supplies may be used in one installation with same, different or dual frequencies.
Examples of very big and very small:
Melting installation MW@60 Hz 80
Soldering installation 250W@300 kHz Chart Courtesy of EFD Induction

Heating Time

Typical processes 1. Continuous processes (wire, rod, billet and strip heating, tube welding, crystal growth etc.) 1 3 4 5 2. Semi -continuous processes (melting, scan hardening and tempering etc.) 3. Single -shot heating 4. Local surface hardening 5. Pulse heating (gear hardening, sealing etc.) Days Hours Minutes Hours Minutes Tens of Tens of seconds Seconds Fraction of Tenths of second seconds

Frequency Selection

Frequency selection is very important for optimal induction process design.
Criteria and factors for frequency selection:
Efficiency of inductor and installation in general
Power factor of the inductor, characterizing reactive power of installation and, therefore, dimensions of matching transformer and capacitor battery
Heating time and corresponding production rate
Hardness depth and heat pattern control
Electrodynamic forces, causing vibration of inductor and machine components and acoustic noise
Cost of equipment and its size

Power Density Curves for Induction

Surface Hardening Process Effectiveness of induction surface hardening strongly depends on frequency selection.
Desired hardness depth At the end of heating cycle when utilizing the optimal frequency the maximum value of power density must be just beyond the required hardness depth (5 mm in the case on right).
For simple cases of flat and round pieces and traditional steels, there are graphs and formulae for frequency selection. However, computer simulation is a much more powerful, universal and accurate design tool.
Part diameter 1.6” (4 cm), frequency 4 kHz, Required hardness depth – 0.2” (5 mm) ELTA simulation program

Recommended Frequency for Different Case Depths

Optimal frequency corresponds to Case Depth = 0.5 δ Good frequency range corresponds to 0.3 δ < Case Depth < 1 δ Case Depth Frequency, kHz 1.0 3.0 10 30 100 300 Min mm 5.0 2.7 1.5 1.0 0.6 0.5 Opt mm 8.0 4.5 2.5 1.6 1.0 0.8 Max mm 15 9.0 5.0 3.0 1.6 1.2

Temperature Evolution During an

Induction Hardening Process Compared to furnace heating induction hardening provides much faster heating when optimal frequency is used.
Flame Heating Using direct flame method, in order to achieve required temperature at a needed depth, surface must be strongly overheated.
Time When using induction, temperature inside the case depth is much more uniform resulting in better quality.
With induction, process may be well controlled and automated.
ELTA simulation

Comparison of Temperature Evolution for Mass Heating

and Surface Hardening Induction heating can provide almost uniform cross-section heating (such as in the case of mass heating) or selective surface heating.
Typical temperature distribution at the end of mass heating corresponds to time t 8. If the workpiece is held inside of inductor with constant surface temperature control (for example during the forge operation pause), temperature inside the billet may be higher than on the surface (curve th).
In surface hardening, frequency must correspond to the desired case depth (h w). Typical final temperature distribution for case hardening of a big shaft corresponds to time t 5. Final curve is flat on the part surface and temperature is close to constant inside the major part of expected case depth, leading to more uniform hardness.
Mass heating Heating for surface hardening

Temperature Color Map for Induction Hardening Process

Computer simulation allows us to predict temperature distribution in the part and optimize the process of heating (power, frequency, time)and quenching (quenchant type, time). Case depth, microstructure and hardness may be predicted for a particular steel.
Heating Quenching Radius For typical steels such as 1040, hardness depth corresponds to temperature isoline 800 degrees C Time ELTA simulation program

Resistivity and Permeability Variation

with Temperature
Electrical resistivity of metals grows with temperature. For carbon steels it grows approximately 6 times from room temperature to typical hardening temperature 850 - 950 C (1550 – 1750 F). For graphite resistivity is almost constant in a wide range of temperatures. Salts, glasses, oxides and some other materials are non-conductive at low temperature
Magnetic permeability of steels remains almost constant until temperature 400 C (750 F). After that it begins to drop and at a certain temperature (called Curie point) material becomes completely non-magnetic (μ = 1). Curie temperature is 710-750 C (1300 – 1380 F) depending on steel type. Alloyed steels may have much lower Curie point
Permeability at room temperature depends on steel type and magnetic field strength, i.e.heating power at a given frequency. For surface hardening μ may be 5-10 while for through heating – 30 and more. It means that penetration depth may change 10-40 times resulting in different coil parameters and heating intensity

Variation of Reference Depth

with Temperature Material – magnetic steel T c –magnetic transformation or Curie temperature. Below this temperature steel is magnetic (μ » 1); above – non-magnetic (μ = 1). For carbon steel T c is close to 750C (~1400F).
Permeability drops when temperature approaches to Curie point.
Due to variation of μ, ρ and reference depth δ, the coil parameters vary in the process of heating.
Material and coil parameter variation is much smaller when heating nonmagnetic materials or magnetic material below Curie temperature (tempering, stress relieving etc.).
Resistivity, permeability and reference depth variation with temperature for carbon steel.
High permeability μ1 corresponds to weaker magnetic field (typical for mass heating); much lower value of μ2 is typical for surface hardening when magnetic field is much stronger.

Typical Power Variation in Surface Hardening

Case of constant coil voltage In a static or single-shot heat treating process, the coil power may drop and then significantly increase when the surface layer gets non-magnetic.
If generator controls are set for constant output current, power dynamics will be very different.
Parameter variation is essential for optimal process and coil design. It may be predicted by computer simulation.
ELTA simulation program

Example of Power Variation in

Mass Heating Process Case of constant coil voltage Maximum power corresponds usually to a thickness of non-magnetic surface layer of 0.5-0.7 of the reference depth in hot metal.
After that coil losses gets higher while the workpiece power drops, i.e. coil efficiency dramatically drops.
Part Dia. 7 cm; frequency 3 kHz ELTA simulation program

Electrodynamic Forces

In induction heating processes Electrodynamic forces usually play a negative role causing coil and part vibration. Vibration can generate harmful noise and also reduce coil lifetime.
Electrodynamic forces are distributed between the system components. At high frequency forces are applied to the coil component surfaces.
The coil copper face always experiences repulsion from the workpiece.
The concentrator poles experience attraction to the workpiece. Resulting force applied to the coil may be either attractive or repulsive (more typical).
For the same workpiece power, the electrodynamic forces become lower with higher frequency.
Electrodynamic forces vary in time.
Electrodynamic forces applied to the coil copper and concentrator poles. Workpiece is a magnetic steel with a locally austenitized (nonmagnetic) zone under the coil face.

Time Variation of Electrodynamic

If coil current waveform is sinusoidal, electrodynamic forces are also sinusoidal but with twice the frequency.
If current frequency is 1 kHz, force and vibration frequency will be 2 kHz, which corresponds to maximum sensitivity of the huma near. Resulting noise may exceed the Max Permissible Level in the work place.
At current frequency 10 kHz and higher acoustic noise is inaudible (except of some “subharmonics”).
Application of Fluxtrol concentrators can reduce noise compared to laminations.
In addition to the oscillating force Fa there is a constant component Fc of a total force F.
Fc produces permanent pressure on the coil and part, which can cause their deformation.

Melt Stirring by Electrodynamic Forces

When applied to molten metal (melting, brazing), electrodynamic forces cause material flow.
In a crucible induction furnace maximum pressure is applied to the metal surface in the middle of the coil where magnetic field is stronger.
Metal flows inside the crucible (stirring effect). Stirring is positive effect that provides better melt composition and temperature uniformity. When the force is too big, it can cause a big meniscus or even squeeze metal out of crucible.
Magnetic concentrators may be useful for electrodynamic force control in molten metal treatment (melting, brazing, casting etc.).

Excessive Electrodynamic Forces

At high and middle frequency, the electrodynamic forces are usually not high and may be well managed.
Forces may be very high when heating large slabs at low or line frequency resulting in damage to induction coil and equipment.
Example:
Aluminum slab 0.3x 1x 3m (2.5 tons) Power 600kW,50Hz Constant arrows) force
7 tons (black Oscillating forces acting on each side of the coil are 7 tons @100 Hz (red arrows)

Electrodynamic Forces Summary

Possible positive effects:
Melt stirring composition in the bath resulting in uniform temperature and metal
Possibility to control liquid metal flow in casting and other processes
Possibility to hold small quantity of molten material levitated inside the inductor without touching coil or crucible walls Negative effects of electrodynamic forces:
Attraction of magnetic particles to the coil and concentrator (magnetic chips move into the areas of the strongest field)
Coil vibration, which in addition to static force and thermal stresses can result in coil deformation or failure of brazed joints
Separation of concentrators from copper and possible shift of loose pieces
Loud noise exceeding Max Permissive Levels on work places
Deformation profiles
Unintended or excessive movement of molten metal or parts of assembly in brazing and melting of heated parts (distortions) especially of thin poles non-round

Electrodynamic Forces Summary (cont.)

Measures for reduction of electromagnetic forces influence:
Coil style and design selection to account for forces
Frequency selection (avoid too low frequency!)
Mechanical design of the coil and concentrator; frequency of mechanical resonance of the coil assembly must be far from double value of current frequency
Reliable manufacturing of coil and concentrator

Conclusions to Basics

There are many mutually coupled phenomena in induction heating systems (electromagnetic, thermal, electrodynamic etc.). Their understanding is essential for a proper design and maintenance of induction coils and installations
Induction coil parameters depend on the workpiece dimensions and temperature distribution. This effect may be used for real-time process monitoring and quality control systems
Absorbed power and temperature distribution in the part may change during the heating time
Magnetic flux control can improve the coil performance
Computer simulation can predict a system behavior and is a powerful tool for study and design of induction heating systems

Questions and Answers

An induction Process can be defined by a combination of?
Power, Time, Frequency
Curie, is the temperature at which a magnetic material becomes ….?
Non-Magnetic
Induction heating effectiveness is strongly dependant on….?
Frequency
Temperature inside the case depth is much more uniform when using flame or induction heating?
Induction Heating
Computer Simulation can predict: Coil parameter variation? Power and temperature distribution? Case depth?
All
Which material properties affecting coil parameters change with temperature?
Electrical Resistivity, Permeability
Resistivity of what materials drops significantly when temperature grows?
Glass, Ceramics, Oxides
In a static or single shot surface hardening application, coil power may drop and then significantly increase when the surface layer of the workpiece….?
Reaches Curie temperature and becomes non-magnetic
For the same workpiece power, electrodynamic forces become lower with ?
Higher Frequency
If coil current frequency is 3 kHz what will be a main frequency of acoustic noise?
6 kHz

R&D for Emerging Technologies

Mon, 01 Jan 0001 00:00:00 +0000

The R&D and Engineering groups of Fluxtrol, Inc. conduct cooperative development of new processes with many world leading companies in food packaging, crystal growth, cold crucible melting, welding carbon fiber composites, etc. We are proud to acknowledge our long-term collaboration with Tetra Pak resulted in great improvement in the performance of its high-speed packaging machines, supplying liquid food to final users worldwide.

Reducing Coil Current & Power Losses (Shielding)

Mon, 01 Jan 0001 00:00:00 +0000

Magnetic flux does not respect equipment boundaries. In an induction system, the field that leaves the coil also reaches machine frames, chambers, fixtures and sensors. Electromagnetic shielding in this context means giving that flux a harmless place to go, so those components stay cool and the coil does not have to work harder to compensate.

Fluxtrol 25

Mon, 01 Jan 0001 00:00:00 +0000

Fluxtrol 25 provides good performance over a wide range of frequencies. The material has the best elasticity of Fluxtrol materials, excellent machinability and reasonable thermal conductivity.

Heat Treating Inductor Styles

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Choosing an induction hardening inductor style

Induction heat treating coils come in many shapes and sizes, and the style depends on the process. Whatever the style, an inductor must meet the heat treatment specification at the required production rate, tolerate manufacturing variation, mount in the machine, match the power supply electrically, deliver quench, last, run efficiently and repeat from coil to coil. This page summarizes the styles described in the ASM Handbook Volume 4C chapter Design and Fabrication of Inductors for Induction Heat Treating. See Methods for single-shot and scan processes.

Induction Coil Manufacturing & Fabrication

Mon, 01 Jan 0001 00:00:00 +0000

Induction coil manufacturing turns an engineered design into a water-cooled copper inductor that carries high current, delivers heat to the part and survives electromagnetic forces, thermal cycling and the shop environment. Fluxtrol builds coils from copper tubing, machined copper or both, and completes them with the structure, quench components and magnetic flux controllers the design calls for. Fabrication follows from coil design and engineering and is checked through the quality and integrity procedures before a coil ships.

Induction Installations

Mon, 01 Jan 0001 00:00:00 +0000

This chapter of the free Fluxtrol induction heating course walks through induction installations in 43 slides. View the slides below, or skim the outline and slide text.

Chapter outline

Induction Installation Structure
Layout of Induction Hardening Installation
Installation with Coil Mounted on Heat Station
Single Platform Installation
Induction Hardening Installation
Power Supply Block Diagram
Power Flow in Induction Heating Installation
Types of Power Supplies
Motor-Generator Sets
Vacuum Tube Generators
Solid State Generators
Modern Solid State Power Supplies
Simultaneous Dual Frequency Power Supplies
Intelligent Power Supplies
Comparison of Power Supplies
Large Solid State Power Supplies /
Large High Frequency Solid State
Mid-Sized Solid State Power
Small Solid State Power Supplies /
Small Solid State Power Supplies
Dual Output Solid State Power Supplies
Dual Output Solid State Power Supply
Power Supply Selection Criteria
Load Matching
Load Matching with Parallel Circuitry
Load Matching with Series Circuitry
Heat Station
Load Matching Transformers
Capacitor Battery
Load Matching Procedure
Power Supply Regulation Modes
Power Connections
Process Control and Monitoring
Layout of Induction Circuit with Sensors
Process Monitors
Part Handling Systems
Water Cooling and Quenching
Typical Closed Loop Water Cooling System
Conclusions
Questions and Answers

Slide text

Induction Installation Structure

Main components of a typical induction installation:
Generator: generates high frequency power from utility line frequency power
Heat Station: matches induction coil to a generator
Handling Mechanisms: load, process and unload parts
Cooling System: provides cooling of installation components (generator, heat station and induction coil)
Quenching System: provides conditioned quenching media to the part
Control and monitor systems: provides control and monitoring process and equipment

Layout of Induction Hardening Installation

Quench system Water cooling system Power Generator Heat station Coil Handling Mechanism/ Machine Machine control

Installation with Coil Mounted on Heat Station

Operator Controls Induction Coil Pusher Heat Station Courtesy of EFD Induction

Single Platform Installation

installation may be:
Quench system
Mounted on a single platform Machine
Distributed
Built in line Water cooling system Power supply Heat station Coil Machine control Single Platform Induction installation:
Requires less space Easy to install Shorter installation time Less expensive to install Utilities required at single point

Induction Hardening Installation

Scanning machine Mains distribution cabinet Frequency Converter Work area:
Inductor
Quench Cooling and quench system Control system cabinet Example of a single-platform induction hardening installation, EFD Induction

Power Supply Block Diagram

Command Control electronics 3 phase line input AC to DC conversion Rectifier section DC to AC Inverter section Load matching transformer & capacitors Induction coil Heat station HF Generator Power supply must convert alternating line frequency power (50 or 60 Hz)into a controlled High Frequency power. The most effective way to do that is to convert (rectify) line frequency power into DC power and then generate high frequency using solid state Inverter.

Modeling & Optimization

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We utilize the latest software versions of Flux 2D/3D and Elta 6.0 for electromagnetic and thermal computer simulation, with the ability to couple the results of simulation with other packages to model complex multiphysical processes such as stress and deformation phenomena. A majority of these projects are the result of industry demand, in cooperation with customers. We use simulation in all research and development projects for profound study of processes and optimal design of induction systems.

SMCs in High-Tech Electromagnetic Devices & Sensors

Mon, 01 Jan 0001 00:00:00 +0000

Soft magnetic composites (SMCs) were developed for induction heating, but the properties that made them useful there also matter anywhere AC magnetic fields are generated, guided or screened. This page sticks to what the published record supports: how SMCs compare with electrical steel laminations and ferrites, and where they have been applied outside conventional heat treating.

Ferrites vs. Soft Magnetic Composites

Mon, 01 Jan 0001 00:00:00 +0000

Engineers choosing a magnetic flux controller for an induction coil have three material families to pick from: ferrites, soft magnetic composites (SMCs) and electrical steel laminations. No one of them wins everywhere, and the right choice depends on frequency, flux density, geometry and cooling. Fluxtrol makes SMCs, so this comparison is drawn from the published ASM Handbook Volume 4C chapter and Fluxtrol’s materials paper, and it names where ferrites and laminations are the better choice.

Ferrotron 559H

Mon, 01 Jan 0001 00:00:00 +0000

Ferrotron 559H provides proven flux concentrator performance with the highest dielectric strength in the Fluxtrol family of machinable soft magnetic materials and lowest losses at high frequencies. Almost constant magnetic permeability over a range of magnetic flux densities and frequencies. Material has good mechanical strength and thermal conductivity. Regarded by many to have the best machinability of the Fluxtrol family of materials.

Induction Coil Quality & Integrity

Mon, 01 Jan 0001 00:00:00 +0000

Induction coil quality and integrity work happens between the last braze joint and the first production part. A coil that leaks, carries residual flux in its cooling passages, or differs electrically from its siblings can fail early or heat parts differently. The procedures below follow the ASM Handbook Volume 4C chapter on inductor design and fabrication, co-authored by Fluxtrol engineers, and complement coil manufacturing .

Induction Coil Styles

Mon, 01 Jan 0001 00:00:00 +0000

This chapter of the free Fluxtrol induction heating course walks through induction coil styles in 24 slides. View the slides below, or skim the outline and slide text.

Chapter outline

Requirements for Induction Coils
Advanced Induction Coil Design
Example of Improved Design of Induction Coil
Induction Coil Types
Evolution from Transformer to Induction Coil
Cylindrical Melting Coils
Cylindrical Multi-turn Forging Coil
Cylindrical Heat Treat Coil
Cylindrical Heat Treat Coil
Scan Hardening Using Single-Shot Inductor
Internal Diameter (ID) Coils
Internal Diameter Multi-turn Coils
Example of I.D. Inductor with External Cooling Ring
More Types of Internal Diameter Coils
Hair-Pin and Split-n-Return Coils
Robot Guided Heating with Hair-Pin Inductor
Channel Coils
Two-turn Channel Coil for Mass Heating
Pancake and Vertical Loop Coils
Coils for Transverse Flux Heating (TFH)
More Induction Coils

Slide text

Requirements for Induction Coils

Induction Coils are the work tools of induction installations.
They must:
Meet specifications to temperature distribution
Have good electrical efficiency
Have a satisfactory life time
Provide desired production rate
Have favorable parameters for efficient energy supply, such as high impedance and power factor
Have low sensitivity to changes in the part dimensions and positioning in specified range
Meet special requirements (quenchant supply, atmosphere, material handling, incorporation into the machine, etc.)
Have reasonable cost In many cases magnetic flux controllers are required to achieve these goals Cost Benefi ts

Advanced Induction Coil Design

Induction coils are essential components of the whole installation and their design and manufacturing quality are very important.
Advanced induction coils design includes:
Detailed analysis environment of specifications, available equipment and
Sometimes a “Design For Induction Heating” Strategy may be applied:
Modification of heat pattern specs
Part geometry modification
Part material change (if possible)
Sequence of operations
Coil style and heating process selection (scanning, single-shot, static etc.)
Computer simulation for coil head optimization
Analysis of benefits of magnetic flux controllers application
Coil engineering (design of coil head, leads, structural components, quenchant supply etc.)
Advanced manufacturing techniques
Tests in laboratory or industrial plant
Final corrections if required for performance

Example of Improved Design of Induction Coil

Quote: “ It is difficult to make a coil that does not work at all” Anatoly S mir nov, old coil master,1958
Addition: But it is difficult to make a coil that fits or exceeds the modern customer expectations!
Magnetic flux control can play a key role in optimal coil design Example of coil optimization using flux controller Original induction coil for plastic coating application of stub shafts produced improper temperature distribution and was subjected to mechanical damage by parts.
New potted coil (left) with local Fluxtrol controller and stainless steel protective cap provides excellent heat pattern control, coil mechanical strength and improved efficiency.
Fluxtrol ring

Induction Coil Types

There are thousands of different induction coil designs with different geometries, dimensions and materials used.
However it is possible to organize all the coils into several major types (styles) and their combinations:
Cylindrical coils Outer Diameter (OD)
Internal (ID) coils
Hair-pin Coils
Split-and-Return Coils
Pancake Coils
Vertical Loop Coils
Single-Shot Coils
Transverse Flux Coils and others

Evolution from Transformer to Induction Coil

Any induction coil may be considered as a “transformer” with a workpiece as a short-circuited secondary winding.
a b c d a. Transformer with two layers of primary winding s and short -circuited secondary (black) b. Transformer type of induction heating coil c. Multi -turn cylindrical coil with magnetic flux concentrator d. Single -turn cylindrical coil with magnetic flux concentrator

Cylindrical Melting Coils

There is a big variety of melting coils in size and design but almost all of them are cylindrical coils.
Frequency range is very wide from line frequency for big furnaces to radiofrequency for melting of small parts, precious metals etc.
Big furnaces usually have lamination shunts for parameter improvement, magnetic field shielding and as construction components.
Small high and middle frequency furnaces usually have no concentrators or shunts.
Flux controllers may be effectively used in vacuum or special atmosphere furnaces mainly for shielding. Right – coil for melting radioactive materials in protective atmosphere. Fluxtrol A shield strongly improved efficiency and power factor and allowed the use of a larger furnace in the same chamber.

Cylindrical Multi-turn Forging Coil

Multi-turn cylindrical or oval coils are used for heating billets, rods and slabs for forging. Typically they have thermal insulation (lining) to reduce heat loss and to protect winding
Application o f external concentrators cannot improve parameters of long forging coils.
Lamination shunts are used sometimes at low frequency to provide rigid frame withstanding electrodynamic forces and to reduce strong external magnetic fields
Local controllers may be used at the coil ends to control temperature distribution in the part and to protect handling mechanisms (rolls etc.) from unintended heating Multi-turn forging induction coil Courtesy VNIITVCh, St. Petersburg, Russia

Cylindrical Heat Treat Coil

There are many varieties of cylindrical heat treating coils with different turn numbers, copper profile, concentrator presence and geometry etc.
They are widely used for local static heating and scanning processes
Concentrators are the most effective on single or two turn coils. They can help in achieving specified heat pattern, improve part quality and increase production rate Single-turn scanning coil with integrated quench and Fluxtrol A concentrator

Cylindrical Heat Treat Coil

CVJ single-shot coil
Widely used for heating of axles, hubs and other relatively short parts especially with varied cross-section. Cylindrical part must rotate.
Requires high power which results in copper being heavily loaded.
Concentrators are required parameters improvement.
for local temperature control and coil

Scan Hardening Using Single-Shot Inductor

Short Single-Shot induction coils may be used for scan hardening of worm shafts and other parts.
Application of concentrators adjusts temperature distribution on tips and root areas.
Fluxtrol Concentrator Courtesy AjaxMagnethermic-TOCCO company

Internal Diameter (ID) Coils

Several types of induction coils may be used for heating of internal surfaces:
Cylindrical single- and multi-turn coils
Hairpin coils
Central Rod coils Cylindrical coils are the most common.
Single-turn scanning coil with Ferrotron 559H core. Quenchant is supplied through the holes in the core All ID coils except Central Rod strongly benefit from use of magnetic concentrator (core).
Two-turn inductor with Fluxtrol core.
Quenchant supplied through the fiberglass tube passing inside the core

Internal Diameter Multi-turn Coils

Single-turn cylindrical ID coils may be used for static heating of short areas and for scanning of long parts
Multi-turn ID coils used for static heating of long zones are more complicated because of return leg passing inside the coil diameter D int.
Magnetic concentrator (core) is critical for improvement of coil efficiency, power factor and current demand. Poles on the concentrator are recommended for better parameters and heat pattern control Left - Multi-turn ID coil with magnetic core Right – two versions of return leg position
It is recommended to make magnetic core of two parts with gap or shift return leg to the coil side in order to reduce additional magnetic field created by return leg
Right – potted 6-turn ID coil with Ferrotron 559H core Magnetic core

Example of I.D. Inductor with External Cooling Ring

This multi-turn ID coil for surface hardening of a thinwall part has an external cooling ring to control hardness depth.
Quenchant inlet External cooling of a part Quenchant is supplied through the magnetic core with outlet holes between the coil turns and in the end area of the core.
Fluxtrol core Coil copper cooling

More Types of Internal Diameter Coils

Central Rod ID coil Hair-Pin ID coil
Central Rod ID coil may be used for heating of small ID bores (less than ten millimeters in diameter). A drawback of this coil is that there must be electrical contacts in current circuit to insert and remove the part
Hair-Pin ID coil requires rotation of the part. Magnetic flux concentrator (core) is necessary for efficient performance of this coil. It is also possible to control power and temperature distribution in the part length by varying concentrator size or material

Hair-Pin and Split-n-Return Coils

Hair-Pin coils are widely used for scanning heating of flat surfaces.
Concentrator strongly improves coil efficiency and power factor
Split –and-Return coils can heat almost rectangular straight zone. May be used for static heating and for scanning mainly in longitudinal direction (tube seam annealing etc.)
Concentrator is strongly recommended for these coils for heating zone control and parameter improvement
This coil is slightly more efficient than Vertical Loop coil but is more bulky

Robot Guided Heating with Hair-Pin Inductor

Hair-Pin coil has two sections without and with concentrator (Fluxtrol A)
Concentrator application provides higher efficiency and allows deep control of the workpiece temperature profile.
For “smooth” control different material types or concentrator dimensions may be used

Channel Coils

Channel coils are used for local heating (annealing, tempering, brazing, curing, forge heating) of different parts (fasteners, cartridges, rod ends etc.)
May be single or multi-turn
Concentrators improve coil efficiency and control temperature distribution in the parts. For quality heating of randomly supplied parts, channel coils must be supplied with current as the constant value. This allows for variable number of pieces to be heated correctly
Brazing channel coil (bottom) has additional magnetic shields (“deconcentrators”) on cross-overs in order to reduce electrodynamic forces on brazing joint components at the coil entrance and exit

Two-turn Channel Coil for Mass Heating

Beam heating before bending operation Local Fluxtrol A concentrators with protective casings

Pancake and Vertical Loop Coils

Pancake induction coil is usually multi-turn. It heats a ring on the surface. Central zone may be heated by heat conduction or coil / part movement such as eccentric part rotation
Concentrator is strongly desirable to improve coil parameters and reduce underheated central zone
Vertical Loop induction coils can heat almost rectangular straight zone. May be used for static heating and for scanning in longitudinal or transversal direction
Concentrator is strongly recommended for these coils. It is desirable to have return copper leg wider than an active leg

Coils for Transverse Flux Heating (TFH)

TFH systems are able to heat very thin parts (strips, bands, plates) at relatively low frequency with high electrical efficiency. They consist of two Hair -Pin or Split-n-Return coils located on opposite sides of the part. Widely used in metallurgy (strip heating) and packaging industry (sealing).
Magnetic flux concentrators are necessary for these coils to provide high efficiency and to control temperature in the width of the part More simple system with magnetic pad instead of one of the coils has parameters between TFH system and hair-pin coil + .
- .
Ф Ф – Magnetic flux + .

More Induction Coils

Many induction coils have complex geometry, which may be composed of several standard types.
This Horse-shoe induction coil was developed for an automotive aluminum heat exchanger in a brazing operation “tube to pipe”. It may be considered as a combination of half-cylindrical coil with two hair-pin coils.
Magnetic controllers are critical for these coils in general and for this application particularly. They permit consistent joint quality with significant coil parameter improvement. Different joints may be brazed with the same coil copper by modifying controllers only.

Induction Forging & Forming

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Rethinking induction forging and forming

Forging and forming shape many of the components used every day, from automotive drivetrains to industrial machinery and energy equipment. Induction heating has become a preferred way to prepare the workpiece because it delivers fast, controllable heat directly in the stock. The harder part is consistent, uniform heating, especially with complex geometries or multi-material components. Fluxtrol’s soft magnetic composite (SMC) flux controllers help engineers tailor heating patterns, improve efficiency and get more consistent results.

Induction Heating for Medical & Science

Mon, 01 Jan 0001 00:00:00 +0000

Fluxtrol’s medical work is research-stage and well documented. Its engineers helped design inductors for cancer hyperthermia studies, in which magnetic nanoparticles targeted at tumors are heated by an alternating magnetic field (AMF). The field is of particular interest for metastatic cancers of the prostate.

On-Site Support

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Once induction coils or other installation components have been designed or produced in our facility, Fluxtrol can provide on-site support at the customer’s site. With experienced set up and run off personnel, including in house metallurgists, material scientists and electromagnetic experts, Fluxtrol prides itself on its concept-to-reality capabilities.

Alpha-form MF

Mon, 01 Jan 0001 00:00:00 +0000

Formable soft magnetic composite developed on the basis of magnetic particles with a thermal-curing epoxy binder. This material may be used for quick and efficient installation to induction heating coils with low tolerances.

Download Alphaform MF Data Sheet
Download Alphaform MF Instructions PDF

Computer Simulation

Mon, 01 Jan 0001 00:00:00 +0000

This chapter of the free Fluxtrol induction heating course walks through computer simulation in 33 slides. View the slides below, or skim the outline and slide text.

Chapter outline

Opening Remarks
Special Features of Induction Heating
Process Design & Coil Design
Computer Simulation vs. Experimental Method
Induction Process and Coil Development via Computer
Interrelated Processes in Induction
Types of Programs for Induction Heating
Rule of Pyramid
ELTA Software Features
When to Use ELTA
ELTA: Describing the Workpiece
ELTA: Inductor and Tank Circuitry
Example: Design of In-Line Heat Treating Process
Design of In-Line Heat Treating Process (cont.)
Design of In-Line Heat Treating Process (cont.)
Design of In-Line Heat Treating Process (cont.)
Report Generated by ELTA
Scanning Simulation Using ELTA
Flux 2D Software
When to Use Flux 2-D Simulation
Coil Styles Favorable for Flux 2D Simulation
Axle Hardening Simulation with Flux 2D
Temperature Profile and Austenitized Zone
Example of Melting Furnace Designed with
When to Use Flux 3-D Simulation
Flux 3D Software Features
Gear Heating Simulation Using Flux 3D
Pipe-to-Tube Brazing Simulation
Accuracy of 2D and 3D Computer Simulation
Conclusions

Slide text

Opening Remarks

First works on computer simulation of induction coils were made in 1960’s. Due to a limited access to computers, their low memory, speed and poor programming methods the computer simulation did not receive significant industrial application until the 1980’s
Now computer simulation has become a practical tool for everyday use in the induction industry. It allows the user to design optimal systems, improve equipment performance, dramatically reduce development time and costs, better understand the process dynamics, etc.
Though there are still difficulties in accurate simulation of non-linear and different mutually-coupled tasks, computer simulation is effectively used for design of induction heating coils and problem solution
Material of this chapter is based mainly on experience of the author, his colleagues and his collaborators in development and use of computer simulation programs in different areas of induction heating

Special Features of Induction Heating

Computer Simulation
The induction heating market is small compared to other industrial sectors and there are only a few specialized simulation packages on the market that can be used for induction process and coil design
Induction heating simulation involves a set of mutually coupled nonlinear phenomena
Many induction applications are unique and may require different program modules
In addition to computer simulation software an extensive database is necessary for accurate results

Process Design & Coil Design

Process Design Coil Design
Optimal Frequency, Power and Time
Coil style selection
Heating style (Static, Scanning, Single-Shot)
Copper cross-section
Magnetic flux controller
Coil matching In many cases we have limited control due to existing machines, dictating frequency and power range and heating style.
This is something we can change to improve the process.

Computer Simulation vs. Experimental Method

Computer Simulation Experimental Method Advantages
Can work for any geometry and operating conditions
Demonstrates the entire dynamics of the process
Leaves records for future
Limitless accuracy of calculations
Does not require special equipment
Less expensive and time consuming
Future improvements expected Advantages
May provide the most reliable results
Can show performance of the whole system including unexpected effects and troubles
Does not require material property database
Provides physical samples for properties validation Limits and Disadvantages
Requires special software and databases
Not all the processes may be simulated (as of today)
Does not provide physical Limits and Disadvantages
May require expensive equipment
Does not provide a good understanding of the process
Difficult to transfer knowledge
Case dependent accuracy
Limited access to production equipment (expensive) samples

Induction Process and Coil Development via Computer

Typical stages of computer -assisted induction coil development:
Induction process design (Power, Frequency, Time)
Induction coil design
Coil engineering and manufacturing
Process set-up and performance validation
Final modification of induction coil and process if required Example: Development of aluminum heat exchanger brazing and experimental validation

Interrelated Processes in Induction

Heating Computer Simulation Process Control Machine Operating Mode Power Supply Circuits Thermal Process (Heating) Electromagnetic Process Cooling / Quenching Stresses Structural Transformations Distortions

Types of Programs for Induction Heating

Computer Simulation at Fluxtrol Inc.
PC Computer Simulation Type Program 1D + Coupled Elta 2D Electromagnetic Flux2D 2D Thermal Flux2D 2D Coupled Flux2D 3D Electromagnetic Flux3D 3D Thermal Flux3D 3D Coupled Flux3D

Rule of Pyramid

Guidelines:
Use least complex software where possible; it can provide final solution in simple cases or reduce optimization area before using more complicated programs
Analyze results to avoid mistakes in program input or setup
There is no universal program that can solve all the problems of induction heating 3D EM + T Flux 3D 3D EM Flux 3D 2D, Structural + Thermal 2D, Electromagnetic + Thermal Flux 2D 1D +, Electromagnetic + Thermal Elta

ELTA Software Features

User friendly interface with very fast solver
Electromagnetic + Thermal
Combines numerical 1D calculations analytical account of the system length
Axisymmetrical geometries
Module for simulating internal coils
Possibility to simulate power supplying circuit (busswork, capacitors, transformer)
Database materials
Option of automatic frequency variation
Automatic report generation selected or created template with (OD & ID) & non-linear plane with parallel properties according of to Scanning process simulation

When to Use ELTA

Valuable for almost all cases to determine optimal process parameters (P,f, t,Quenching) and coil style
May be used for coil design
Determine number of turns for proper matching
Large (relative to part uniform heating areas size),
Scanning applications
Very valuable for in-field support, new project evaluation and presentations
Multi- stage and multi - inductor process simulation possible
Valuable training learning

ELTA: Describing the Workpiece

Material property database screen Workpiece description screen Specific heat vs.
temperature for carbon steel

ELTA: Inductor and Tank Circuitry

Screen for description of Tank Circuitry Screen for description of Inductor

Example: Design of In-Line Heat Treating Process

ELTA simulation program
In-Line processes are more and more popular in industry
Durations of all stages of in-line process (Austenization, Quenching, Tempering and Final Cooling) must be coordinated Task: Hardening and tempering of the shaft end
Diameter – 40 mm
Length – 60 mm
Case depth – 4 mm
Steel 1040

Design of In-Line Heat Treating Process (cont.)

Simulation showed that minimum time for austenization heating is slightly under 4 sec. at optimal frequency 3kHz Load/Unload Austenitizing Quenching Tempering Cooling This time was selected as a base for other stages:
Austenization 4sec
Quenching 8 sec
Tempering 4+4sec
Final cooling 8 sec Rotary table machine with 8 positions was selected for heat treating. Two positions were used for tempering AUST ENITI ZING TEMPERING t QUENCH COOLING

Design of In-Line Heat Treating Process (cont.)

Temperature evolution in optimized process:
Green
part surface Red
center Black
temperature differential Color Map of temperature distribution shows that at the end of the first stage a depth of austenitized layer (T> 800 C) is 4 mm as required.
After 8-second quenching, temperature at the depth of 4 mm dropped below 120 C, which is sufficient for complete martensite transformation, while temperature at the center remained around 300 C.
This residual temperature and twostage heating for tempering provided very uniform temperature in hardened layer during tempering process.
E LTA Software

Design of In-Line Heat Treating Process (cont.)

Time , m c , sec 3D presentation of temperature evolution a R s u i d E LTA Cooling curves for different radii Software

Report Generated by ELTA

Date: 2/25/2006 3:26:06 PM Version: 3.3 Project: Induction hardening Heat Sources Density 3 6000 Page 5 of 5 P, W/cm t=0.8 4000 t=1.5439 t=2.386 t=3.1579 t=4 2000 r, cm 0 0 0.5 1 1.5 2 Heat source (power density) distribution in the workpiece 1E005 Power P, W Generator Inductor Coil losses 50000 Workpiece Leads 0 0 5 10 15 20 25 t, s 30

Scanning Simulation Using ELTA

with concentrator water no concentrator water Color map and isolines of temperature generated by the program Scanning heating of watercooled plate demonstrating effect of Fluxtrol Concentrator See Robotic System video on next slide

Flux 2D Software

Major software for precise analysis and optimization of induction coils with concentrators
Electromagnetic modules
Material database with nonlinear properties
Scanning possible
Heating process available animation
Can simulate circuits external
Can work in conjunction with other software (AutoCAD, Mat Lab, Attila, etc.) + Thermal simulation Temperature distribution and magnetic field lines of Split-n-Return coil in seam annealing application

When to Use Flux 2-D Simulation

Process and coil design
Part dimensions/heat pattern changes
Heat pattern is not uniform in length and the need exists to optimize distribution of temperature
Part & coil have rotational or planar symmetry (or partial symmetry)

Coil Styles Favorable for Flux 2D Simulation

Cylindrical Coils
Vertical Loop Coils
Hairpin Coils
Cylindrical ID Coils
Pancake Coils
Split-n-Return Coils (partially)
Channel Coils Ability to accurately simulate the system also strongly depends upon part geometry and motion mode (rotation, scanning etc.)

Axle Hardening Simulation with Flux 2D

Fluxtrol Coil Copper A B Geometry of fillet area and induction coil (Zone A – B must be hardened) Water Passage Axle Magnetic field lines at 3kHz with Fluxtrol A concentrator

Temperature Profile and Austenitized Zone

Frequency 3 kHz Final temperature distribution Austenitized layer, which will correspond to hardened zone after quenching

Example of Melting Furnace Designed with

FLUX 2D Computer Simulation Dry (air-cooled) induction furnace for special material melting.
Coil is made of Litz cable and potted. Fluxtrol Concentrator plates are used to decrease current demand and improve efficiency.
They are used also as radiators for heat transfer from the coil to inert gas in the chamber.

When to Use Flux 3-D Simulation

When good information and results cannot be achieved using 2-D with reasonable approximations
Evaluate 3-D effects for some systems where 2D is used with some assumptions (lead area in cylindrical coils, cross-over parts of single-short coils etc.)
Understand some uncertain effects from experiments
Simulation of strongly 3D systems/ processes such as gear hardening, welding, some brazing systems etc.
3D system composed from 2D coil and 2D parts

Flux 3D Software Features

May be Electromagnetic, Thermal or Coupled
Material database with non-linear properties is available
Usage Considerations
More complicated and less user friendly than Flux 2D
Requires powerful computers for reasonable calculation times
Time and knowledge consuming for problem formulation, geometry description and calculation process setup (mesh building etc.)

Gear Heating Simulation Using Flux 3D

Eddy current density distribution in a quarter of a gear tooth Frequency 50 kHz, concentrator - Ferrotron 559H; gear modulus is 5 mm.
Maximum current density is in root area near the tooth end.

Pipe-to-Tube Brazing Simulation

Head of heat Tube Brazing joint Pipe Color map of optimal power density distribution between the components of aluminum heat exchanger (see more details in Case Stories)

Accuracy of 2D and 3D Computer Simulation

Simulation accuracy depends upon:

Accuracy of system geometry description 2. Accuracy of description of material parameters such as quenching intensity properties processing 3. Problem formulation; there are several options how to describe the electromagnetic field in 3D systems 4. Number, distribution and type of elements of simulation mesh 5. Algorithms used in the program and software quality Position 1 is the most important for 2D simulation, when the user needs to neglect 3D effects of real induction systems (such as lead area in a cylindrical coil, “spirality” of multi-turn coils etc.).

Calculation errors may be reduced to negligible values by means of proper selection of mesh and calculation process parameters.
Accuracy of simulation also depends on experience knowledge of the user especially in 3D simulation cases.

Conclusions

At present time personal computers are powerful simulation of most induction heating problems enough
1D and 2D simulation are well established in induction industry
3D simulation is an emerging technology
Computer simulation is a powerful tool for:
Induction process and equipment design
Optimal design of induction coils
Research and development
Development of databases of processes, projects and coil designs
Troubleshooting
Advertisements and business presentations
Training, education and self-education New advances in computers, software and data bases of material properties will lead to wider and more effective use of computer simulation in induction heating !

Custom Magnetic Flux Controllers

Mon, 01 Jan 0001 00:00:00 +0000

A custom magnetic flux controller is a concentrator, shield or core cut or formed to suit one coil. Fluxtrol soft magnetic composites (SMCs) are built for this: machinable Fluxtrol and Ferrotron blocks are fit to the inductor, and formable Alpha-form is molded in place. This page explains what controllers do, how they are made, and where to go for machining and assembly detail. Controller design is part of coil design and engineering .

Ferrotron 559H Original

Mon, 01 Jan 0001 00:00:00 +0000

Similar to Ferrotron 559H standard, Original has nearly constant permeability over a wide range of flux densities and excellent machinability. When compared to Ferrotron 559H, Original has better mechanical strength, higher magnetic permeability, saturation flux density and thermal conductivity. These improvements do come at a cost of dielectric strength and magnetic losses.

Induction Shrink Fitting

Mon, 01 Jan 0001 00:00:00 +0000

What is induction shrink fitting?

Shrink fitting assembles two parts with an interference fit: the mating dimension of one part is smaller than the other at the same temperature. Heating the outer part makes it expand through thermal expansion, so it slips over the inner part, and as it cools it contracts and grips. Induction heating is a natural fit because it heats metal quickly, locally and without contact.

Personal Training

Mon, 01 Jan 0001 00:00:00 +0000

CIT organizes courses at the Fluxtrol facility for individuals and groups of industrials, which include specifically tailored lectures on theory and simulation as well as practical training in coil design and manufacturing, magnetic controller installation and the process setup and demonstration. Example of such event is a 3-day course for 8 operators and engineers from Mexico. A set of lectures was followed by hands-on training program and visits to the coil companies.

Alpha-form LF

Mon, 01 Jan 0001 00:00:00 +0000

Download Alphaform LF Data Sheet
Download Alphaform LF Instructions PDF

Induction Annealing

Mon, 01 Jan 0001 00:00:00 +0000

Induction annealing and stress relieving

Annealing is a heat treatment applied to relieve stress or improve microstructure. Induction suits it when the treatment is local, as in the weld seam of a tube, and when it must be fast, repeatable and in-line. Induction heating also covers hardening and tempering; see Metal Hardening . Fluxtrol’s experience concentrates on seam annealing and stress relieving of welded pipe, supported by research on strip annealing.

Magnetic Flux Control

Mon, 01 Jan 0001 00:00:00 +0000

This chapter of the free Fluxtrol induction heating course walks through magnetic flux control in 39 slides. View the slides below, or skim the outline and slide text.

Chapter outline

What is Magnetic Flux Control?
Combination of Several Effects of
Possible Improvements due to Application of
Effects of Magnetic Flux Controllers
Improvements Expected for O.D. Coils
Melting Inductor for Glove Box Environment
Effects of Magnetic Flux Controllers
Improvements Expected for I.D. Coils
Example of Magnetic Core Influence
Effects of Magnetic Flux Controller
Improvements Expected
Robotic Induction Heating using Hairpin Coil
Other Coil Styles Where Concentrators
Example: Single-Shot Coil with Fluxtrol 50
Materials for Magnetic Flux Control
Magnetic Permeability
Simulation Study of Permeability Influence
Results: Coil Current Demand vs. Permeability
Results: Total Power vs. Permeability
Losses in Magnetic Materials
Hysteresis Losses
Hysteresis Loop of Soft Magnetic Materials
Local Eddy Current Losses
Global Eddy Current Losses
Dependence of Total Loss Upon
Electrical “Resistance” of Composite Material
Resistance and Resistivity
“Touch” Resistance
Electrical Resistivity Measurement
Considerations for Magnetic Controller
Magnetodielectric Fluxtrol Materials
Laminations
Ferrites
General Guidelines for Selecting the
Conclusions
Questions / Answers

Slide text

What is Magnetic Flux Control?

In this course magnetic flux control is a generic term for modification of induction coil magnetic flux by means of installation of magnetic templates (magnetic flux controllers). Magnetic flux control due to application of non-magnetic bodies (Faraday rings or flux robbers) is not considered here.
Magnetic controllers may significantly change magnetic field pattern and coil parameters; their application must be considered as a part of the whole induction system design.
Because Controllers play different roles (magnetic flux concentration, shielding, distribution) they are called also Concentrators, Cores or Shields depending on application.
In many cases controllers fulfill several functions simultaneously.

Combination of Several Effects of

Magnetic Flux Controllers Optimal power distribution between the system components.
Flux 3D program Part: Aluminum heat exchanger Operation: Tube-to-Pipe brazing Concentrator effects:
Optimal power distribution between Tube and Pipe
Controlled shielding of the head of heat exchanger
Total efficiency improvement resulting in heating time reduction from 25 to 15 sec
Variation of Fluxtrol concentrator allows the use of the same coil copper for brazing a family of products Stories) (see more details in Case

Possible Improvements due to Application of

Magnetic Flux Controllers
Precise heat pattern control
Power saving or production rate increase due to improvement of induction coil efficiency and better utilization of power in the workpiece
Lower current demand for the same power
Extended coil lifetime
Improvement in power supply performance due to higher coil power factor and lower current demand
Shielding of part or machine components from unintended heating
Reduction or elimination of external magnetic fields (safety and electromagnetic compatibility issues)

Effects of Magnetic Flux Controllers

on O.D. Coils The role of magnetic flux controllers and their effects may be explained and evaluated by composition of magnetic flux circuit similar to electric current circuit.
Φ = IN / (Zm + Rm)
Φ (phi) – Magnetic Flux causing heating
IN – Ampere turns of the coil (driving force of magnetic flux)
Zm – Magnetic resistance (Reluctance) of the “active zone”
Rm – Magnetic resistance for magnetic flux on return path
B – Magnetic Flux Density (Induction). It describes magnetic loading of controller material.
Φ Zm B Rm IN Applying controller we reduce Rm and therefore increase magnetic flux with the same coil current or reduce current demand for the same flux and heating power. Effect of controller is higher when Rm is high compared to Zm.

Improvements Expected for O.D. Coils

Improved Heat fillet, etc.) Pattern /Ability to Heat Difficult Areas (axle
Better Utilization of Power in Workpiece for short static coil (energy savings up to 30%)
Lower Coil Current and therefore reduced losses in supplying circuitry – transformer, capacitors, busswork
Shielding of part and machine components from unintended heating
For long OD coils –small or no coil parameter improvement. However, in some cases local temperature control and shielding is required – see coil on slide 4.
Heat treating of some difficult application of flux controller parts can not be achieved without

Melting Inductor for Glove Box Environment

Induction coil for melting of radioactive materials in protective atmosphere Example of shielding effect efficiency improvement and Fluxtrol A plates Fluxtrol A shields on the side and bottom coil surfaces allowed to:
Strongly reduce losses in the chamber walls and bottom plate
Increase the furnace volume in the same chamber
Increase coil efficiency from 23 to 63% due to reduced losses in chamber walls, bottom plate and in the coil Glove Box walls Fluxtrol plates Molten metal Magnetic field lines and color map of power density in a shielded coil with molten metal

Effects of Magnetic Flux Controllers

on I.D. Coils
In ID coils magnetic flux must return back around the turns in narrow space inside the coil and therefore magnetic resistance Rm is usually high
Concentrator (core) dramatically reduces coil current required to push the flux on return path
When the core is installed, magnetic flux and power are much higher with the same coil current or current demand is much lower for the same power Φ Zm Rm IN

Improvements Expected for I.D. Coils

Shorter heating time
Substantial energy savings (oftentimes 40-50% or more)
Strongly improved electrical efficiency
Drastically reduced current demand
Reduced losses in power supplying circuitry
Heat pattern control Single-turn I.D. induction coil with Fluxtrol A concentrator

Example of Magnetic Core Influence

on Parameters of I.D. Coil With the same pipe power, application of core reduced coil current from 2000 A to 900 and corresponding reactive power from 65.8to 30.2kVAr.
Electrical efficiency of the coil increased from 69% to 84%.
Coil head voltage remained almost the same (5% increase) Flux 2D program

Effects of Magnetic Flux Controller

on Hairpin Coils
Magnetic resistance of the back path is mainly due to limited space between the coil legs
Central pole is critical; side poles are less important though they further reduce current demand
Application of MFC to a part of the coil provides strong control of power distribution in the part along the coil I I Rm Φ/2 Φ/2 Zm/2 Zm/2

Improvements Expected

for Hairpin and Transverse Flux Coils
Shorter heating times
Substantial energy savings
Greatly control improved heat pattern
Drastically reduced current demand
Reduced losses in power supplying circuitry
Transverse flux heating possibility to provide uniform heating in the edge areas Example of concentrator influence when applied to hairpin coil (see details on next slide)

Robotic Induction Heating using Hairpin Coil

1. Installation:
Powersupply –30kW,30kHz Robot
Courtesy ABB Stand – Stainless steel curved plate with water cooling on internal surface (Special design of Fluxtrol Inc.) 2. Induction coil has two equal sections, one of them has Fluxtrol A concentrator.
Note: Dramatic difference in heat intensity between coil sections without and with concentrator

Other Coil Styles Where Concentrators

Improve Performance Dramatically
Pancake Coil
Split-n-Return
Vertical Loop
Single-Shot
Channel Coils
Transverse Flux Heating Coils
Any coil where there is limited space for back path flow of magnetic flux .
- - .

Example: Single-Shot Coil with Fluxtrol 50

Fluxtrol 50 concentrators (yellow) are placed in strategic areas of the coil Concentrators are mechanically attached to copper while good thermal contact provided by glue

Materials for Magnetic Flux Control

Available materials belong to three major groups:
MagnetoDielectrics (MD) such as Fluxtrol & Ferrotron materials
Laminations
Ferrites
Magnetodielectrics or Soft Magnetic Composites (SMC) are made of magnetic particles and different binders. Combination of magnetic particle material and size, binder type and manufacturing technology gives a big variety of MD with different properties
Laminations are thin sheets of special electrical steel with insulation on their surface
Ferrites are glass-like materials made of oxides of iron, manganese, zinc and other elements Fluxtrol Inc. produces 3 primary MD materials:
Fluxtrol A
Fluxtrol 50
Ferrotron 559 H

Magnetic Permeability

For different materials and operating conditions (temperature, magnetic field strength) permeability may vary in a wide range from 1 to several thousands
Permeability is the main characteristic of material responsible for effects produced by controllers. However, research conducted by Fluxtrol Inc. show that permeability under 100 is sufficient for a majority of induction heating applications (see following slides)
Materials with low saturation flux density (ferrites) cannot support high permeability at high magnetic loading (B)
Requirement of high permeability is usually in contradiction to other characteristics such as electrical resistance and machinability
Influence of permeability on controller performance may be predicted by computer simulation

Simulation Study of Permeability Influence

on Process Parameters Workpiece:
Flat body composed of a central part B (under the coil face) and two side areas
Material – magnetic or nonmagnetic steel Conditions:
Linear single-turn inductor
Same temperature under the coil face
Same heating time Considered parameters:
1. Current demand 2. Power demand A – side areas, B – work area Gap 4 mm; Coil face width 19 mm Frequencies 3 and 10 kHz

Results: Coil Current Demand vs. Permeability

Coil Current vs. Perm.
50 kW In Part Under Coil Face 750 0 L1cm-Mag-gap4mm-3kHz Magnetic part L1cm-Mag-gap4mm-10kHz 600 0 L1cm-Non-gap4mm-3 kHz Current (A) L1cm-Non-gap4mm-10kHz Non-magnetic part 450 0 3500 300 0 150 0 0 1 10 100 Rel. Perm 100 0 Permeability Concentrator reduces current demand 40 - 50% at permeability 40 - 50 compared to permeability 1 (air).
Notice: very small improvement at higher permeability for all studied cases

Results: Total Power vs. Permeability

Total Power vs. Perm.
50 kW In Part Under Coil Face 150000 L1cm-Mag-gap4mm-3kHz 140000 L1cm-Mag-gap4mm-10kHz 130000 L1cm-Non-gap4mm-3 kHz 120000 Power (W) Magnetic part L1cm-Non-gap4mm-10kHz Non-magnetic part 110000 100000 90000 80000 70000 60000 50000 1 10 100 Rel. Perm 1000 Permeability Concentrator reduces power demand 25 - 30% at permeability 20 - 40.
Notice: no improvement at higher permeability for all studied cases

Losses in Magnetic Materials

Losses depend on material type, frequency and magnetic flux density inside the material
Concentrator copper losses are usually much lower
Losses are responsible for concentrator reliable performance of concentrator than losses temperature in and the coil therefore
High thermal conductivity and proper concentrator cooling can concentrator temperature under control even when losses are high There are three types of losses in magnetic materials:
Hysteresis losses
Losses due to eddy currents in the concentrator body (“global” eddy currents)
Eddy current losses in individual components or areas (lamination sheets, metal particles in MD) due to “local” eddy currents.
keep

Hysteresis Losses

Caused by “internal friction” of micro volumes (magnetic domains) of magnetic material in the process of their re-orientation in alternating magnetic field
Depend on magnetic material nature and operating conditions
Do not depend on particle resistivity of material size (or sheet thickness) and electrical
Are approximately proportional to magnetic field frequency
Annealed materials have lower hysteresis losses
Hysteresis losses depend upon the area of Hysteresis Loop (next slide)

Hysteresis Loop of Soft Magnetic Materials

Main magnetic properties may be described by Hysteresis Loop of material:
Magnetically “soft” materials have a narrow loop with small coercive force.
Magnetization When coercive force is small, the whole Curve loop transforms in one curve (magnetization curve of ideal material without hysteresis)
Magnetization curve reaches a threshold limit – saturation - with strong magnetizing force (i.e. at high value of magnetic field strength)
Permeability is usually calculated from magnetization curve as B/H for each Hysteresis loop of “soft” magnetic material. Width of the loop is enlarged here for better visualization point of the curve
In case of real materials magnetized by B AC magnetic field, B moves along the loop borders (a – b – c – d – e – f – a) when H changes from max to min values
Magnetic loop is important because magnetic losses for hysteresis are proportional to a product of its area and H frequency
See more information about terms in magnetics in Glossary Real hysteresis loop of Fluxtrol 25

Local Eddy Current Losses

B
In Laminations:
depend on frequency, steel grade, sheet thickness and their orientation in magnetic field
In Magnetodielectrics:
depend on frequency, magnetic particle size and orientation (for nonround particle shape)
depend upon resistivity and permeability of the particle material
Local losses are approximately proportional to magnetic field density square and frequency square Local eddy currents in laminations B
For higher frequency, particle size or sheet thickness must be smaller to keep losses under control Local eddy currents in magnetic composite particles

Global Eddy Current Losses

Depend on the concentrator size and shape
Depend on the “global” resistivity of material electrical
Depend square frequency on magnetic field
May be reduced by electrical separation of individual parts of concentrator if necessary
When surface conductivity due to particle smearing is high, etching eliminates additional losses (see slides on etching) Insulation layer prevents conductor short – circuiting through the concentrator and may reduce losses due to “global” induced current

Dependence of Total Loss Upon

Frequency and Flux Density
For the same flux density always grow with frequency losses
For low frequency proportional to frequency losses)
For high frequency range they are approximately proportional to frequency square (eddy current losses)
Losses depend square (B 2) on flux they are (hysteresis density Lo ss es LF material HF material Frequency B Material selection must take into account both material losses and thermal conductivity for their removal in order to keep under control the concentrator temperature F1 F2 Total losses in two magnetic materials for a given flux density F1, F2 – recommended frequency limits

Electrical “Resistance” of Composite Material

Higher The Better! But high resistance is in contradiction to magnetic and thermal properties…
Depends on material type and surface conditions (as pressed, machined, ground, sand-blasted,…)
Insufficient resistance can result in:
Possible short circuiting between the coil turns through the concentrator
Loss increase due “global” eddy currents to induced Coil short circuiting along a conductive surface of concentrator

Resistance and Resistivity

In general Resistance is a parameter of electrical component (resistor)
When applied to a piece of any material, it is a resistance of the whole piece. It depends on a body size, dimensions and material property (Resistivity). Resistance will also depend upon the points of application of measuring device contacts and local contact resistance
Resistivity ρ is a characteristic of material, not of a body; it equals to resistance of material volume unit
To calculate resistivity, resistance of a piece of material with a regular crosssection must first be measured
Resistivity equals to a body resistance divided by its length and multiplied by cross-section; measured in Ohm cm or Ohm inch (see next slides on resistivity measurement) L S - sample cross-section R – electrical resistance Resistivity ρ = RS/L

“Touch” Resistance

It is a common practice to apply contacts of Ohmmeter (Multimeter) to a piece of material and measure resistance. It may be called “touch” resistance

Fluxtrol Laminate Replacement Material (LRM)

Mon, 01 Jan 0001 00:00:00 +0000

The leading lamination replacement material

Fluxtrol LRM offers a highly efficient and cost-effective alternative to traditional laminations for induction coil applications. By choosing Fluxtrol LRM, manufacturers can significantly reduce construction time compared to standard lamination builds. Our material is available in near-net shapes and can be finished to precise sizes to meet your specific requirements. Furthermore, Fluxtrol LRM provides superior thermal performance, allowing induction coil copper to operate at lower temperatures versus traditional laminations, while also benefiting from our fast delivery capabilities

Fluxtrol Soft Magnetic Composites on Induction Coils

Mon, 01 Jan 0001 00:00:00 +0000

This chapter of the free Fluxtrol induction heating course walks through fluxtrol soft magnetic composites on induction coils in 39 slides. View the slides below, or skim the outline and slide text.

Chapter outline

Materials Manufactured by Fluxtrol Inc.
Fluxtrol Material Features
Uses of Fluxtrol Materials in Induction Heating
Properties of Fluxtrol
Fluxtrol Primary Products
Magnetization Curves for Fluxtrol Products
Magnetic Permeability of Fluxtrol Products
Material Anisotropy
Anisotropy of Fluxtrol Materials
Optimal Cutting of Fluxtrol Material from Blank Stock
Electrical Resistivity and Resistance
Touch Resistance of Machined Parts
Material Selection
Guidelines for Fluxtrol Material Selection
Fluxtrol Products General Selection Guide
Fluxtrol Products General Selection Guide
Fluxtrol Materials
Etching
Machining
Mechanical Properties
Fluxtrol Material Coating
Attachment Methods
Mechanical Attachment
Application Technique for Heavy Loaded Coils
Example of Concentrator Application to Hairpin Coil
Concentrator Temperature Control
Temperature Distribution in Fluxtrol Controllers
Thermal Conductivity for Fluxtrol & Adhesive Materials
Maintenance of Coils with Fluxtrol Concentrators
Examples of
Mass Heating Inductor for Bending Operation
Replacement of Laminations with Fluxtrol Materials
C-shaped Concentrators Matching
Brazing of Heavy Copper Bars for Nuclear Plants
Conclusions
Questions

Slide text

Materials Manufactured by Fluxtrol Inc.

Fluxtrol Inc. is a world leading manufacturer of magnetodielectric materials for induction heating controllers Primary materials:
Fluxtrol A
Fluxtrol 50
Ferrotron 559H Fluxtrol Inc. also manufactures other standard and custom materials:
Ferrotron 119
Fluxtrol 25
Custom materials Fluxtrol Inc. manufacturers a big variety of sizes and shapes. Special shapes may be made on request Materials in the Fluxtrol and Ferrotron families, which are designed primarily for induction heating, may be used in many other applications (as sensors, antennas etc.)

Fluxtrol Material Features

Fluxtrol and Ferrotron materials cover the whole frequency range used in induction heating
Magnetic permeability is sufficient for induction heating applications
All materials have excellent machinability and good mechanical strength; they may be used as structural components of the coil
Ferrotron materials have good electrical strength and may withstand applied voltage up to several hundred volts
Temperature resistance is high enough; in critical additional measures of thermal management may be used applications
Losses may be removed by quenchant, by contact to the coil tubing, by special cooling plates or water channels machined directly into the material
All materials are resistant to oil, hot water and polymer quenchants;
small surface rusting may be prevented by etching or coating

Uses of Fluxtrol Materials in Induction Heating

Major applications:
Cylindrical OD coils for static hardening
Single-turn OD scan coils (parts with a sharp fillet)
Complex coils (wheel hubs, CVJ stems, etc.)
ID coils (cylinder liners, ID gears, etc.)
Channel coils (fasteners, machine tool brazing, etc.)
Gear heat treating coils (single and dual frequency, tooth by tooth etc.)
Local heating for bending and other deformation
Brazing and soldering Emerging applications:
Single shot coils for axles and shafts
Rotational crankshaft coils
Seam annealing coils
Induction tempering
Packaging technology
Shielding of workpiece and equipment parts
Inductive coupled low temperature plasma
Impeders for tube welding Induction coil for CVJ hardening with Fluxtrol concentrators

Properties of Fluxtrol

and Ferrotron Materials

Fluxtrol Primary Products

Note: frequency ranges and resistivity values are only for reference

Magnetization Curves for Fluxtrol Products

Flux Density vs Magnetic Field Strength Flux Density, Gs 14000 12000 10000 Fluxtrol A 8000 Fluxtrol 50 6000 Ferrotron 559 H 4000 2000 0 0 50 100 150 200 Field Strength, A/cm Compared to laminations and ferrites, Fluxtrol materials are almost linear. This means that Fluxtrol controllers do not generate distortions in coil currents or voltage waveforms. Distortions result in additional reactive power of the coil and additional losses in transformer and capacitor battery.

Induction Heating for Materials Production

Mon, 01 Jan 0001 00:00:00 +0000

Materials production draws on Fluxtrol’s melting research. The legacy company text lists special metallurgy among the industries where its solutions are used, and the R&D description names cold crucible melting and crystal growth among its cooperative development areas.

Cold crucible melting

Cold crucible furnaces (CCFs) melt metals, oxides, glasses and other materials, and they are inherently three-dimensional, which makes them hard to model. Fluxtrol’s 2013 study reported that electrical efficiency was low, approximately 25-30% for metals and lower for some materials, and found that system-level optimization with magnetic flux controllers could improve it strongly. The theory was confirmed by laboratory mockups and industrial melting tests. See the paper and the cold wall crucible development paper .

Case Story – Design of Stress Relieving Coil and Process

Mon, 01 Jan 0001 00:00:00 +0000

This chapter of the free Fluxtrol induction heating course walks through case story – design of stress relieving coil and process in 12 slides. View the slides below, or skim the outline and slide text.

Chapter outline

$avings Due to Induction Coil and Process Optimization
Problem Description
Step 1: Analysis of Process Conditions
Step 2: Simulation of Existing Process
Step 3: Initial Inductor Design Using Power Ramping
Step 4: Optimal Process and Coil
Temperature Evolution with New Coil
New Inductor Sketch (Top and Side Views)
Final Results

Slide text

$avings Due to Induction Coil and Process Optimization

Increased production rates
Lower maintenance costs
Fewer downstream operations
Reduced part scrap
Shorter change-over times
Energy savings Everyone must produce “Good Parts”, but there are ways to make them Better, Faster and more Economically !

Problem Description

Problem:
The Customer the following:
made contact due
System they purchase d could meet required production rate to not
To achieve marginal parts, they had to run at half the promised speed
Even at half speed, they did not meet customer specifications because the heated zone was too narrow and the part was experiencing low temperature on seam bottom
Difficulties were because the machine was built based upon experience in seam annealing, not stress relieving Inductor for seam annealing on spiral welded big diameter pipe

Step 1: Analysis of Process Conditions

Limited space on spiral welding mill
Power supply and other equipment with frequency 3 kHz and power 500 kW already exists
Heat tube material:
Steel 1040
Wall thickness 12.7 mm
Relatively small temperature window
Tmax = 650 C
Tmin = 550 C
Heat Affected Zone (HAZ) 60 mm
Required heating time 16 seconds
Flux concentrator: Laminations on original coil later replaced with Fluxtrol “A”

Step 2: Simulation of Existing Process

Temperature evolution in Outside (1) and Inside (2) seam points These results are close to experimental data and very far from specifications Temperature color end of heating map Flux 2D program at the

Step 3: Initial Inductor Design Using Power Ramping

The easiest way to improve temperature distribution is to use power profiling along the coil length. It may be achieved by variation of concentrator geometry.
Results are much better but specifications are still not met

Step 4: Optimal Process and Coil

Proposed solution:
1. Make central coil leg of two parallel conductors to increase Heat Affected Zone 2. Power ramping holding temperature and precise maximum 3. Use Fluxtrol concentrator with profile variation Temperature color map for new coil and process at the end of heating

Temperature Evolution with New Coil

Temperature evolution in Outside (1) and Inside (2) seam points for optimized process Temperature profile along the pipe OD surface at the end of heating Minimum temperature in HAZ (point 2) reached required material exceeding maximum acceptable temperature value without

New Inductor Sketch (Top and Side Views)

Concentrator has full C-shaped profile at ramping stage. When maximum permissible temperature was reached, concentrator shape started to change by cutting pole length then complete removal of concentrator.
Top view of concentrator (hatch ed) Fluxtrol concentrator Fluxtrol concentrator Side view of induction coil

Final Results

Customer manufactured induction coil according to Fluxtrol suggestions
Induction user was able to produce parts in specs with desired production rate
Final customer was completely satisfied See Seam Anneal Video

Induction Coating, Bonding & Adhesive Heating

Mon, 01 Jan 0001 00:00:00 +0000

Contactless heat for bonding, curing and joining

Induction bonding and curing systems heat a part, bond line or coating with an alternating magnetic field instead of a flame, oven or hot tool. Heat is generated inside the workpiece, so cycles can be fast and tightly localized, and nothing has to touch the part. That makes induction a natural fit for adhesive heating, curing and the joining of composites.

Induction Heating for Steel Sheet Processing

Mon, 01 Jan 0001 00:00:00 +0000

Steel sheet processing is a research frontier for Fluxtrol, not an established product line. A 2025 collaboration explored replacing gas-fired furnaces in continuous annealing lines with rapid induction heating for advanced high-strength steels (AHSS).

The project

Led by Alec Williamson of the Colorado School of Mines and supported by U.S. Steel, Cleveland-Cliffs, AIST and Fluxtrol, the work had these objectives:

Case Story – Wheel Hub Heat Treating

Mon, 01 Jan 0001 00:00:00 +0000

This chapter of the free Fluxtrol induction heating course walks through case story – wheel hub heat treating in 8 slides. View the slides below, or skim the outline and slide text.

Chapter outline

Problem Description
Step 1: Analysis of Inductor Failure
Development Strategy
Step 3: Development of New Induction Coil Using
Tests of New Coil

Slide text

Problem Description

Heated part:
Single-race wheel hub Problem:
The Customer made contact due to the following:
Short coil life – (8,000 – 13,000 pieces) resulting in:
Machine downtime
Unacceptable personnel time due to extended set-up
Scrap parts Note: Inductor repair costs not a problem in this case due to manufacturer warranty Typical process of induction heating of wheel hubs

Step 1: Analysis of Inductor Failure

Coil failure modes:
Copper cracking under laminations due to overheating
Lamination degradation Previously attempted actions:
Very high water pressure and flow rate did not solve the problem
Partial installation of Fluxtrol “A” concentrator instead of laminations improved the situation but did not solve the problem Old coil with partial replacement of laminations with Fluxtrol “A”

Development Strategy

Step 2. (Band Aid)
Complete replacement of laminations with Fluxtrol “A” on existing coil resulted in:
Lower local concentration of power in copper
Same heat pattern and machine settings
Coil Lifetime increased to 15,000 – 25,000 pieces Step 3. (Optimal Solution)
Design new coil with computer simulation
Build and test new coil lower power concentration in copper using

Step 3: Development of New Induction Coil Using

Computer Simulation Temperature distribution in part with new coil design Predicted hardness pattern Flux 2D program

Tests of New Coil

New coil with Fluxtrol “A” concentrator was designed, manufactured and tested in production line.
Heat pattern and coil performance were very close to parameters predicted by computer simulation.
Coil life and part production increased to >170,000 hits without coil copper failure or concentrator degradation.
New induction coil after 170,000 heating cycles

Induction Melting & Stirring

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Melting efficiency starts with the magnetic field

An induction melting furnace transfers power from a coil to the metal charge through a magnetic field. Anything that field does outside the charge, heating the frame, the crucible walls, the chamber or the coil itself, is lost power. Magnetic flux controllers made from Fluxtrol soft magnetic composites (SMCs) steer that field so more of it works on the melt.

Case Story – Surface Hardening of Truck Axle

Mon, 01 Jan 0001 00:00:00 +0000

This chapter of the free Fluxtrol induction heating course walks through case story – surface hardening of truck axle in 11 slides. View the slides below, or skim the outline and slide text.

Chapter outline

Problem Description and Specifications
Step 1: Analysis of Results Obtained with
Step 2a: Simulation of the Process
Step 2 a: Temperature Distribution at the End of the Dwell
Step 2b: Simulation of the Process
Temperature Distribution at the End of the
Step 3: Development of Optimized Coil
Temperature Distribution at the

Slide text

Problem Description and Specifications

The customer contacted Fluxtrol Inc. for the following reasons:
They were unable to produce good parts for a contract they had won
The problem was the new part had a sharper fillet than other parts they had worked with before X In order to get the required depth in the fillet, they had to severely overheat the area (X) just above it resulting in almost through hardening

Step 1: Analysis of Results Obtained with

Existing Equipment
Customer had the necessary equipment (dual-spindle scanner and powersupply 400kW,1kHz)
Customer had 2 standard scan coils that they attempted to use for the process
Single turn coil came closer to achieving the desired results, but production rate was low during scanning
Twoturn coil could produce parts faster, but could not properly heat the fillet area

Step 2a: Simulation of the Process

with Existing Single Turn Coil Simulation of the process with a singleturn coil without a magnetic flux controller clearly showed overheating of the stem near fillet area (in good agreement with tests results) Temperature distribution and magnetic field lines at the end of dwelling period Flux 2D program

Step 2 a: Temperature Distribution at the End of the Dwell

Temperature range 20–1150C Temperature range 800–1150C Results: Marginal depth in the radius, severe overheating in the area above the radius (temperature over 1150C,which would continue to grow in the beginning of the scanning process)

Step 2b: Simulation of the Process

with Existing Two-Turn Coil Temperature distribution and magnetic field lines at the end of dwell Flux 2D program

Temperature Distribution at the End of the

Dwell with Two-Turn Coil Temperature range 20–1135C Temperature range 800–1135C Results: Insufficient depth in the radius and short pattern on fillet, severe overheating in the area above the radius (temperature over 1130C,which would continue to grow in the beginning of the scanning process).

Step 3: Development of Optimized Coil

Based on results of computer simulation and previous experience it was decided to design a twoturn coil with Fluxtrol concentrator on the lower turn.
This design provides a favorable temperature distribution with required hardness depth on fillet and well controlled preheating of the stem area by the upper turn.
Optimal temperature distribution was achieved by variation of crosssections of copper and magnetic concentrator made from Fluxtrol “A”.
Temperature distribution and magnetic field lines at the end of dwell

Temperature Distribution at the

End of the Dwell with Optimized Coil Temperature range 20–1020C Temperature range above 800C corresponding to a total hardness depth Results: Good depth in the radius, no significant overheating in the area above the radius (temperature less than 1020 C); high scan speed/ production rate

Induction Heating for Crystal Growth

Mon, 01 Jan 0001 00:00:00 +0000

Induction heating for crystal growth

Induction heating is used in crystal growth processes, where temperature fields must be controlled precisely. Fluxtrol’s R&D and engineering groups conduct cooperative development of new processes with many world-leading companies in fields including crystal growth, cold crucible melting and the welding of carbon fiber composites.

Case Story – Induction Brazing of Aluminum Heat Exchanger

Mon, 01 Jan 0001 00:00:00 +0000

This chapter of the free Fluxtrol induction heating course walks through case story – induction brazing of aluminum heat exchanger in 9 slides. View the slides below, or skim the outline and slide text.

Chapter outline

Problem Description
System Geometry Description
Step 1: Simulation of Existing Process
Step 2: Development of Induction
Step 3: Optimal Coil and Process Design
Final Results

Slide text

Problem Description

Part: Aluminum heat exchanger Operation: Brazing of a pipe to a short tube previously brazed to the heat exchanger header in a furnace Equipment: All equipment including 60kW,10-30kHz powersupply, part handling system and control system with IR pyrometers already existed Problems:
Insufficient brazed joint depth
Inconsistent process resulting in leakage and other defects Variables:
Limited coil type modification
Coil dimensions
Coil positioning
Magnetic controller dimensions Connection block Pipe coil with magnetic controller joint Tube Header Body Experimental brazing in Fluxtrol laboratory

System Geometry Description

Existing inductors had a “horseshoe hairpin” shape for simple part loading. The coils consisted of two hair-pin sections connected in series with diagonal cross -over.
Geometry is clearly 3D with multiple components (pipe, tube, header, coil copper, magnetic controllers). Due to planes of symmetry it was possible to simulate only ¼ of system.
Non -symmetry due crossovers was neglected.
t o Geometry prepared for simulation using Flux 3D program

Step 1: Simulation of Existing Process

On a base of process analysis it was assumed that the main noncontrolled variable was an electrical contact between pipe and tube.
These components are preliminarily coated with flux and electrical contact between them is unstable.
When the joint is filled with molten filler metal, contact is good.
Computer simulation confirmed this theory. With no electrical contact there i s a strong heat concentration on the tube edge closest to the coil. Overheating of this area is a common defect of brazing.
With good contact current flows from tube to pipe resulting in heat pattern change. It is not possible to balance these two patterns achieving stable quality.
- - Coil currents direction and magnetic generic field lines for horseshoe coil with diagonal crossover Current density distribution in joint area for diagonal crossover.
Left – no electrical contact Right – good electrical contact

Step 2: Development of Induction

Coil with Horizontal Crossover For a coil with horizontal crossover currents flow mainly inside of each component for good and no contact conditions.
However, computer simulation showed that heating of pipe and tube is very weak compared to the heat exchanger header.
Small heating of header is useful for support of temperature profile in the tube, but main power must be delivered to pipe and tube in a correct proportion.
- .
- Coil currents direction and magnetic generic field lines for horseshoe coil with horizontal crossover Current density distribution in joint area for horizontal crossover.
Left – no electrical contact Right – good electrical contact

Step 3: Optimal Coil and Process Design

Additional magnetic controller was placed between the coil bottom and header surface. Variation of magnetic flux controllers made of Fluxtrol “A” material allowed the process to achieve optimal power distribution between all three heat exchanger components.
Laboratory tests confirmed stable process flow and good quality of brazed parts.
Final coil design for one of the brazing joints Additional consideration:
It was noticed that change of crossover resulted in much stronger electrodynamic forces.
Coil tends to “open” when power is turned ON.To reduce effect of electrodynamic forces, an additional fiberglass connector was installed on the coil.
Optimized power distribution in brazing joint components

Final Results

Computer simulation helped to understand the factors causing brazing inconsistency and optimized coil design
Combination of coil copper optimization and proper geometry of magnetic flux controllers solved a problem of brazing quality. There were no more part rejects caused by improper induction heating
It was found that a variety of products may be brazed by the coils with the same copper by adjusting geometry of magnetic flux controllers
Brazing cycle reduced by 15-30% when using new coils

Inductively Coupled Plasma (ICP)

Mon, 01 Jan 0001 00:00:00 +0000

Induction-based plasma systems

Inductively coupled plasma (ICP) systems use a coil-generated alternating magnetic field to sustain a plasma. Like any induction process, their performance depends on coil design and on how the magnetic field is shaped and contained. Those are Fluxtrol’s core competencies.

Historical Overview of Induction Melting and Heating

Mon, 01 Jan 0001 00:00:00 +0000

This chapter of the free Fluxtrol induction heating course covers historical overview of induction melting and heating (44 slides). The slides are image-based, so view them in the viewer above or download the PDF.

Induction Material Processing (Powders, Mixing)

Mon, 01 Jan 0001 00:00:00 +0000

Electromagnetic processing of materials

Beyond heating, alternating magnetic fields do mechanical work on conductive materials. Fluxtrol’s published research describes AC magnetic systems used for material stirring, casting, pouring control, transportation and forming, working across frequencies from DC to several hundred kilohertz.

Fluxtrol Co-Sponsors IFHTSE 2026 Student Poster Award + Connect with our team in Padova

Fri, 14 Aug 2026 00:00:00 -0400

Off-Line Computational & Physical Testing of SMC Impeder Cores and Upcoming Events

Sun, 12 Jul 2026 00:00:00 -0400

How do you test upgrades to your HF tube welding process without interrupting production?

In traditional high-frequency (HF) tube and pipe welding, evaluating new impeder materials usually means running live mill trials—which carries significant operational risks and costly downtime.

In a newly published research article in MDPI Applied Sciences, Rob Goldstein (Executive Director of Strategic Planning & Product Development at Fluxtrol) and his co-authors present a proven off-line methodology combining multi-physics simulation (FEA/CFD) with specialized laboratory test stands to de-risk SMC impeder design.

The Industry Standard for Magnetic Flux Control

Fri, 12 Jun 2026 00:00:00 -0400

Deep Dive: The Industry Standard for Magnetic Flux Control

Did you know that Fluxtrol’s own Robert Goldstein, FASM, authored the definitive section on Magnetic Flux Controllers for the ASM Handbook Volume 4C?

If you are looking for a rigorous, technical foundation on how these materials influence induction systems, this is the essential reference. The article bridges the gap between fundamental electromagnetic theory (like Faraday’s and Lenz’s Laws) and practical, real-world coil design.

Fluxtrol on the Ground in Düsseldorf for Tube 2026

Tue, 12 May 2026 00:00:00 -0400

Last month, the Fluxtrol team traveled to Düsseldorf, Germany, to attend Tube 2026, the world’s leading international tube and pipe trade fair.

While we didn’t have a standalone booth this year, our presence was felt across the exhibition floor as we connected with industry leaders and long-time partners.

Sponsoring Student Innovation: Fluxtrol at Heat Treat Mexico 2026

Thu, 12 Mar 2026 00:00:00 -0400

Heat Treat returns to Monterrey, Mexico, April 14-16th, 2026. ASM International’s 3 day conference is the premier hub for the latest in global thermal processing.

The conference features technical exhibits and educational workshops covering a wide range of induction heating topics. Heat Treat provides hands-on technical experience with the industry’s top innovators, along with unmatched networking connections with the global heat treating community.

Video Demonstration: See the Difference on 5 Inductor Geometries with and without Fluxtrol 25

Sun, 01 Feb 2026 00:00:00 -0500

Watch how essential induction coil types behave when optimized with Fluxtrol’s high-performance soft magnetic composites (SMCs).

In our technical demonstration, we provide a side-by-side look at the physical magnetic field patterns of five common inductor geometries. By comparing these coils with and without Fluxtrol 25, you can clearly see how flux control transforms an inefficient standard process into a fully optimized one, geared toward reducing cycle times and lowering energy consumption.

New Video Demo: Boost Coil Efficiency with Alphaform

Tue, 06 Jan 2026 00:00:00 -0500

See how a standard hairpin induction coil transforms when you add Alphaform soft magnetic composite.

In our short side‑by‑side demonstration, the same coil is run first bare on the left, then with Alphaform applied to the outside of the copper on the right.

Fluxtrol Presents: Improving High-Frequency Tube Welding with Soft Magnetic Composite Impeder Cores

Mon, 01 Dec 2025 00:00:00 -0500

In our latest recorded video presentation, Fluxtrol’s Rob Goldstein, FASM, breaks down how Soft Magnetic Composite (SMC) impeder cores can dramatically improve high-frequency tube welding performance, resulting in lower energy consumption and decreased emissions at the same production speed. Ultimately this leads to increased throughput, uptime, and profitability.

Fluxtrol Inc. & ASM Heat Treating Society Give Awards to Young Scientists at Heat Treat 2025 Conference

Thu, 06 Nov 2025 00:00:00 -0500

Fluxtrol Sponsors Student Competition at Heat Treat 2025

Fluxtrol was proud to sponsor the student competition at “Heat Treat 2025” held by The ASM (American Society of Materials) Heat Treating Society. This year marked The ASM Heat Treating Society’s 34th annual conference and exhibition, conducted between OCTOBER 21 – 23 | located at Huntington Place, 1 Washington Blvd. Detroit, MI 48226.

Fluxtrol Sponsors Student Research Competition at Heat Treat 2025

Sat, 01 Nov 2025 00:00:00 -0400

Fluxtrol was proud to sponsor the Student Research Competition at Heat Treat 2025, supporting the next generation of innovators in thermal processing and materials science. The event featured outstanding student projects that pushed the boundaries of heat-treating technology, with participants presenting their research to a panel of industry experts. By investing in student initiatives like this, Fluxtrol continues its commitment to advancing education, fostering innovation, and strengthening the future of the heat-treating community.

Fluxtrol Presents Research at the 10th International Scientific Colloquium, Leibniz University Hannover

Wed, 01 Oct 2025 00:00:00 -0400

Sean Muysken’s of Fluxtrol presented research on improving the sustainability of induction tube welding systems through soft magnetic composites at the 10th International Scientific Colloquium, hosted by the Institute of Electrotechnology at Leibniz University Hannover, Germany.

Highlights & Findings from Sean’s Presentation Include:

Fluxtrol Showcases SMC Impeder Technology at FABTECH 2025

Mon, 01 Sep 2025 00:00:00 -0400

At this year’s FABTECH 2025, Rob Goldstein, FASM, from Fluxtrol presented exciting new research on how Soft Magnetic Composite (SMC) impeder cores are reshaping high-frequency tube welding.

Key benefits demonstrated in the presentation include:

✅ Generates annual savings of hundreds of thousands of dollars per line by improving operational efficiency.

Are Your Quench Probe Readings Missing the Full Picture?

Wed, 20 Aug 2025 00:00:00 -0400

Spray quenchents are a common choice in induction heat treating and much faster than traditional immersion quenchants. But when it comes to measuring and characterizing these spray quenchants, standard probes often cannot keep up.

In Fluxtrol’s latest study, Limitations of Standard Probes for the Measurement of Spray Quenching, Robert C. Goldstein and D. Scott MacKenzie found:

Induction Heating vs Gas Furnaces: Advancing Sustainable Steel Processing

Thu, 19 Jun 2025 00:00:00 -0400

Excited to share the results of a collaborative research project exploring how induction heating can replace traditional gas-fired furnaces in continuous annealing lines for advanced high-strength steels (AHSS). Led by Alec Williamson from Colorado School of Mines and supported by U.S. Steel, Cleveland-Cliffs, AIST, and Fluxtrol, this work shows:

Fluxtrol Supports Global Heat Treating Community at 2025 QDE Conference | May 2025

Fri, 30 May 2025 00:00:00 -0400

Fluxtrol was proud to serve as a Corporate Sponsor of the 3rd International Conference on Quenching and Distortion Engineering (QDE) in Vancouver.
As a global leader in magnetic flux control for induction heating, Fluxtrol is committed to supporting both cutting-edge industry advancements and the next generation of engineers and researchers. In addition to our corporate sponsorship, we were honored to sponsor the Student Research Competition, an initiative that highlights emerging talent and forward-thinking research in the field of heat treating and materials science.

Advancing Induction Heating Technology for Sustainable Processing and Property Enhancement for Advanced High Strength Sheet Steels

Wed, 01 Jan 2025 00:00:00 -0500

Cooling Requirements for Soft Magnetic Composite Impeders in Inductive Tube Welding Installations

Wed, 01 Jan 2025 00:00:00 -0500

Improving HF Tube Welding System Performance Using SMC Impeder Cores

Wed, 01 Jan 2025 00:00:00 -0500

Information

Authors: Rob Goldstein and Sean Muyskens

Watch on YouTube

Fluxtrol Executive Director of Strategic Planning and Product Development Robert Goldstein, FASM Speaks at HTS

Mon, 09 Dec 2024 00:00:00 -0500

Maximizing Small Diameter Inductive Tube Welding System Performance

Detroit, December 9th – Fluxtrol Inc. is pleased to announce that its Executive Director, Robert Goldstein, will present at an ASM International HTS webinar on December 19, 2024 at 1:00 PM EST.

Robert S. Ruffini Fluxtrol Student Research Award at HEAT TREAT 2023

Wed, 11 Oct 2023 00:00:00 -0400

Fluxtrol Inc. and ASM Heat Treating Society give awards to young scientists who are making strides in the field of thermal processing.

Metro-Detroit, October 9 /BusinessWire/ – The ASM (American Society of Materials) Heat Treating Society is holding their 32nd annual conference and exhibition, “Heat Treat 2023,” OCTOBER 17 – 19 | located at Huntington Place, 1 Washington Blvd. Detroit, MI 48226.

Robert S. Ruffini Innovation and Entrepreneurship Award

Wed, 21 Jun 2023 00:00:00 -0400

HES-23 - International Conference on Heating by Electromagnetic in Padua, Italy

Detroit, June 21 / BusinessWire / - On May 10th to 12th, 2023, the HES-23 International Conference on Heating by Electromagnetic was hosted in Padua, Italy, by LEP – the Laboratory for Electroheat - Padua Department of Industrial Engineering University of Padua. The event was attended by delegates from around the world, who shared presentations on the latest advances in the field. With a focus on innovation and collaboration, the conference was a great success, showcasing the latest research and developments in this area of induction heating technology.

Fluxtrol’s Executive Director of Strategic Planning and Product Development is elected to ASM Fellow of Society (FASM)

Tue, 21 Feb 2023 00:00:00 -0500

Robert Goldstein is honored by the American Society of Materials

Detroit, February 21st /BusinessWire/ - Fluxtrol Inc. is pleased to announce that our very own Executive Director, Robert Goldstein, has been recognized as an ASM Fellow of the Society (FASM), for seminal work on induction heat treating applications, making significant contributions to diverse areas such as human health, space exploration and materials processing.

Fluxtrol and ASM International Announce the 2022 Winners of the Academic Researchers Award and Fluxtrol Student Research Awards

Tue, 24 Jan 2023 00:00:00 -0500

Fluxtrol Inc. Sponsors Heat Treatment Poster Competition at the 2022 IFHTSE World Congress in Austria

Fri, 23 Dec 2022 00:00:00 -0500

Fluxtrol Releases New Immersive Educational Animated Series

Tue, 23 Nov 2021 00:00:00 -0500

Fluxtrol Releases New Immersive Educational Animated Series\

“Fluxtrol Man Makes Screen Debut as Comic Super Hero”

Metro-Detroit, November 23, 2021 /BusinessWire/ – Fluxtrol Incorporated® announced “The Adventures of Fluxtrol Man,” a new interactive animated series designed to educate and entertain audiences, while revealing Fluxtrol’s innovative line of products and services.

Fluxtrol Inc., and ASM International Announce the Winner of the Academic and Student Research Competitions at Heat Treat 2021

Tue, 26 Oct 2021 00:00:00 -0400

IMAT 21 Investigating Temperature Profile in Induction Heated Billets and As-Cast Grain Structure Using Computer Simulation

Fri, 01 Jan 2021 00:00:00 -0500

Information

Authors: Tareq Eddir (Fluxtrol Inc.), Robert C. Goldstein (Fluxtrol Inc.), Robert Haun (Anspanner LLC)
Location/Venue: IMAT 2021 St. Louis, Missouri

Outline

Billet Casters Background
Process Description
Geometry Description
Simulation Description
Power Density Results
Temperature Results
Grain Structure Examples
Conclusions and Future Work

Background

Additive manufacturing of Ti alloys requires specific powder size ranges
Size range of powder production methods is larger than AM techniques can use
Oversize or undersize powder fractions are not usable in most applications of components produced by hot isostatic pressing
Most oversize or undersize powder is sold as an alloy addition for steel making
To recycle oversize or undersize powder for reuse, the powder must be consolidated for EiGA or other drip melting applications
Those companies with cold wall induction crucible melting and bottom or tilt pouring equipment can easily remelt out of specification powder

Titanium Alloy Powder

Typical titanium aluminide power. It is typical for some of the particles to be broken.

UIE 2021 Investigating the Benefit of Soft Magnetic Composite Inserts on Energy Efficiency in Cold Wall Billet Casters Using Computer Simulation

Fri, 01 Jan 2021 00:00:00 -0500

Information

Authors: Tareq Eddir (Fluxtrol Inc.), Robert C. Goldstein (Fluxtrol Inc.), Robert Haun (Anspanner LLC)
Location/Venue: UIE 2021 Pilsen, Czech Republic

Outline

Cold Wall Induction Billet Casters background
Geometry Description
Simulation Description
Electrical Parameter Results
Current Density Results
Conclusions

Background

Titanium powder production has increased substantially for additive manufacturing and the aerospace industry
Powder is manufactured via techniques such as EIGA, which results in a relatively non-uniform powder size
Additive manufacturing of titanium parts requires uniform powder sizes, resulting in low yields of acceptable powder sizes
Rejected powder is recycled through cold wall billet casters
- The cold wall design results in low electrical efficiency
Soft magnetic composites have shown to increase efficiency of cold crucibles and may help reduce power demand in billet casters as well

Geometry Description

Fluxtrol to Continue Safe Uninterrupted Manufacturing and Supply Chain During COVID-19

Tue, 17 Mar 2020 00:00:00 -0400

Fluxtrol COVID-19 Announcement

Metro-Detroit, March 17, 2020 – With the increasing news and concern regarding the COVID-19, Fluxtrol wants to ensure our customers that we are monitoring the developing situation and have resources in place to provide you with materials and continued service in any type of contingency situation.

Fluxtrol Student and Academic Research Awards at the IMAT 2020 Debut

Tue, 04 Feb 2020 00:00:00 -0500

During the IMAT 2020 conference, Fluxtrol, and ASM International, will recognize and award young scientists and academic researchers in the field of thermal processing.

Metro-Detroit, February 4, 2020 /BusinessWire/ – It is an honor to announce this year’s competition-based award and recognition program at the upcoming debut of ASM International’s IMAT 2020—the International Materials Applications & Technologies Conference and Exhibition in Cleveland, Ohio from September 14-17, 2020. IMAT 2020 will offer young innovative scientists/professionals and academic researchers the following two competition-based recognition programs.

Professor Valentin S. Nemkov Academic Research Award and Fluxtrol Student Research Award Winners Announced at HEAT TREAT 2019

Thu, 17 Oct 2019 00:00:00 -0400

Fluxtrol Inc. Taps Producer Stephen Sadler, Author Josef Bastian, Marvel Artist Patrick McEvoy, to Develop New Educational Comic Book Superhero Series, The Adventures of Fluxtrol Man

Tue, 15 Oct 2019 00:00:00 -0400

Metro-Detroit, October 15, 2019 /BusinessWire/ – In late 2018, Robert Ruffini, President of Fluxtrol Inc., and Producer / Writer / Digital Strategist, Stephen Sadler (SCATE) , started discussing a project with a simple goal in mind – to create a unique way to tell Fluxtrol’s story.

Prof. Valentin S. Nemkov Academic Research Award and the Fluxtrol Student Research Award – HEAT TREAT 2019

Fri, 01 Feb 2019 00:00:00 -0500

During the HEAT TREAT 2019 conference, Fluxtrol Inc., in conjunction with the ASM Heat Treating Society, will be recognizing and awarding academic researchers and young scientists in the field of thermal processing.

Metro-Detroit, February 1, 2019 /BusinessWire/ – The ASM (American Society of Materials) Heat Treating Society is holding their 30th annual conference and exhibition, “Heat Treat 2019,” October 15-17, 2019 at COBO Center in Detroit, Michigan.

Fluxtrol Inc., and ASM Heat Treating Society, Recognized and Awarded Student and Academic Research in the field of Thermal Processing

Tue, 17 Jul 2018 00:00:00 -0400

Fluxtrol Inc. presented two awards during the 2018 ASM Heat Treating Society Thermal Processing in Motion Conference.

Metro-Detroit, July 17, 2018 /BusinessWire/ – Fluxtrol Inc. presented two awards during the Thermal Processing in Motion conference held June 5-7, 2018 in Spartanburg, South Carolina. The Fluxtrol/ASM awards given were the Student Research Award and Academic Research Award / Scholarship.

Fluxtrol and ASM Heat Treating Society to Award Student and Academic Research in Thermal Processing

Wed, 18 Apr 2018 00:00:00 -0400

Fluxtrol Inc., in conjunction with the ASM Heat Treating Society, will be recognizing and awarding student and academic research in the field of thermal processing.

Metro-Detroit, April 18, 2018 /BusinessWire/ – The ASM (American Society of Materials) Heat Treating Society and IFHTSE are joining together to present “Thermal Processing in Motion, including the 4th International Conference on Heat Treatment and Surface Engineering in Automotive Applications” on June 5-7, 2018 in Spartanburg, South Carolina.

Modeling of the Heating Sequences of Lightweight Steel/Aluminum Bimaterial Billets for Hot Forging and Hot Hydroforging

Thu, 18 Feb 2016 00:00:00 -0500

Download Full Paper

Abstract

Recently, a concept to produce lightweight products by hot forging a steel shell that had a lightweight core was presented that could lead to component weight savings up to 50%. Some targeted products are gears, valves, and flanges. The steel shell is envisioned to carry most of the load in a target application while the lightweight core serves as a space holder during the forming process. After forming, the lightweight material may either remain in the component and contribute to the load carrying capacity, or be emptied out to achieve the ultimate weight reduction.

Design and Fabrication of Inductors for Induction Heat Treating

Wed, 01 Jan 2014 00:00:00 -0500

Information

Authors: R. Goldstein, W. Stuehr and M. Black
Publication: ASM International, 2014

Buy ASM Handbook Volume 4C

FOR INDUCTION MELTING AND MASS HEATING, the early induction heating coils were manufactured from copper tubing wrapped in multiple turns around a mandrel. The first induction heat treating coils were developed for crankshaft hardening in the 1930s (Fig. 1, 2) (Ref 1–4). Unlike the melting and mass heating coils, the heat treating induction heating coils were machined. These inductors consisted of two parts with a hinge on one side that would open and shut around the crankshaft journal. Quench holes were drilled on the inner diameter of the induction heating coil to deliver quench to the part after heating. This pioneering development was the culmination of many years of hard work by a large team and clearly demonstrated the different requirements for induction heat treating as compared to melting and mass heating.

Magnetic Flux Control in Induction Systems

Wed, 01 Jan 2014 00:00:00 -0500

Abstract

Magnetic flux controllers are widely used in induction heating systems for concentration, shielding or redistribution of the magnetic field which generates power in the part to be heated. Controllers, made of Soft Magnetic Composites (SMC), provide accurate heat pattern control, improve parameters of inductors and performance of the entire installation. In melting systems, especially in the case of vacuum furnaces, cold crucible and other specialty furnaces, the magnetic control can provide large energy savings, magnetic field shielding, shorter melting cycles and optimized field distribution for enhancement of the metallurgical processes. Due to the diversity of applications, service conditions of controllers are very different including very severe cases. Mechanical, magnetic, electrical, thermal and other properties must be considered in design and application of SMC. This article describes properties and performance of SMC typically used in induction heating technology. Several presented case stories are based on more than 20 years of R&D and practical experience of scientists and practitioners at Fluxtrol, Inc. Presented material may be interesting not only for induction heating community but also for all people using AC magnetic fields in technological processes.

Magnetic flux Controllers in Induction Heating and Melting

Wed, 01 Jan 2014 00:00:00 -0500

Information

Authors: R. Goldstein
Publication: ASM International, 2014

Buy ASM Handbook Volume 4C

MAGNETIC FLUX CONTROLLERS are materials other than the copper coil that are used in induction systems to alter the flow of the magnetic field. Magnetic flux controllers used in power supplying components are not considered in this article.

Assembling SMCs on an Induction Coil

Mon, 01 Jan 0001 00:00:00 +0000

Assembling

Adhesive bonding (gluing) is the most common method of attaching Fluxtrol concentrators to an induction heating coil. The user must clearly understand the goals of bonding: whether it’s only to keep the controller on the coil or also to provide its intensive cooling by means of heat transfer to the water-cooled coil turns.

Cookie Policy

Mon, 01 Jan 0001 00:00:00 +0000

Effective Date: February 25, 2026

This Cookie Policy explains how Fluxtrol Inc. uses cookies and similar tracking technologies when you visit our website. By using our site, you agree to the use of cookies as described below.

1. What are Cookies?

Cookies are small text files placed on your device (computer, smartphone, or tablet) by websites you visit. They are widely used to make websites work more efficiently and to provide information to the owners of the site.

Induction Brazing & Soldering

Mon, 01 Jan 0001 00:00:00 +0000

A smarter approach to brazing and soldering with controlled induction heating

Induction brazing and soldering are among the most widely used modern manufacturing processes. Applying heat with efficiency and precision is critical to producing the heat exchangers, electronics and many other parts we rely on every day. Achieving the desired heating pattern, however, requires careful control of magnetic fields and coil design.

Machining Safety & Fire Precautions

Mon, 01 Jan 0001 00:00:00 +0000

Machining Safety Tips:

Use general safety precautions for metal machining when machining Fluxtrol material.
Chips produced during machining may be in the form of curls (typical for Ferrotron materials), small chips or powder. They are not hazardous; see Material Safety Data Sheets (MSDS).
Solid pieces of Fluxtrol materials don’t support fire when heated but accumulated machining dust or debris could support a smoldering fire.
The primary source of combustion is friction. Red hot chips or “sparks” may be thrown off, fall or drop into the debris collection tray of a lathe, bandsaw, milling or grinding machine.

Fire Precautions:

Use machining conditions that don’t produce “sparks”.
Clean all collection (or “catch”) trays before machining Fluxtrol & Ferrotron concentrators, removing any remnant debris.
Use water, wet rags or CO2 extinguisher to extinguish any glowing/smoldering areas.
Never use vacuum cleaner type dust collectors to catch falling dust or debris. Instead, use an approved dust collector over the machining operation. This is best for removing all airborne particles.
Inspect by spreading dust and/or debris for accidental combustion during and after machining operations.
DO NOT INHALE SMOKE OR FUMES.

Privacy Policy

Mon, 01 Jan 0001 00:00:00 +0000

Website Privacy Policy

Last Updated: February 25, 2026

This Privacy Policy explains how Fluxtrol Inc. (“we”, “us”, or “our”) collects, uses, and protects your personal information. By using our website or providing us with your data, you agree to the practices described in this policy.

Protecting SMC Flux Controllers

Mon, 01 Jan 0001 00:00:00 +0000

Magnetic Controller Protection

In many applications Fluxtrol controllers work in special conditions. Factors that can thwart use of controllers and the coil copper or cause their premature failure:

Mechanical damage by the part or during the coil installation.
Material overheating resulting in crumbling. Overheating may be caused by insufficient cooling of the coil, improper design and manufacturing or by concentrator separation from the coil tubing due to cracks in glue.
Environmental impact. In vacuum furnaces special attention must be paid to controller cooling because of absence of convection. Aggressive atmospheres can cause chemical degradation of the controller.
Electrical discharge from one living part to another or to ground can cause arcing and material “burning”.
Many means and methods may be used for protection.

Mechanical damage is one of the main factors in coil / concentrator failure and proper preventive measures must be taken:

Research / Analysis Engineer

Mon, 01 Jan 0001 00:00:00 +0000

Job Summary

We are searching for an experienced and talented Research/Analysis Engineer to join our design and product development team. This key position requires the engineer to also be responsible for project management of assigned FEA and product development projects. This includes the ability to manage a contributing team, meet customer requirements, and complete project timing milestones.

Terms & Conditions of Sale

Mon, 01 Jan 0001 00:00:00 +0000

Download Terms and Conditions PDF

Terms and Conditions of Sale

Applicability

These Terms and Conditions of Sale apply to all Quotations and to all Order Acknowledgments (collectively and individually referred to as “QOA”s) issued by Fluxtrol, Inc. (“Seller”) for all goods and/or services (“Products”) sold and/or performed by Seller. As stated on the face of Seller’s Order Acknowledgment, Seller is unwilling to accept any purchase order unless the purchaser identified in Seller’s Quotation (“Purchaser”) that is submitting the order assents to Seller’s different and additional terms stated in these Terms and Conditions of Sale.