V. Nemkov, R. J. Madeira, N. Vyshinskaya, R. Ruffini, Fluxtrol Incorporated, Auburn Hills, MI
Performance of induction heat treating coils may be significantly improved by application of magnetic flux controllers. They are used to concentrate, shield and redistribute the magnetic field which generates power in the part. Utilizing magnetic flux controllers results in excellent heat pattern control. The efficiency of the entire power delivery system increases when magnetic flux contollers are used to improve the coil performance. Several groups of materials may be used for magnetic flux control: laminations, ferrites and magnetodielectrics, aka soft magnetic composites (SMC). By conducting a comparison of these different materials, it is clear that SMC’s have the most favorable combination of properties for induction heat treating applications. Different grades of SMC may cover the whole range of frequencies used in induction heat treating from 50/60 Hz to more than 1 MHz. They are easily machinable, have sufficient magnetic properties, and good temperature resistance. Conclusive evidence is presented that proves that proper application of SMC concentrators instead of laminations can significantly increase the inductor life time.
Several examples of magnetic flux control illustrate the presented material. This presentation is based on more than 15 years of intensive R&D and practical experience of scientists and practitioners at Fluxtrol Incorporated.
Summary: Magnetic flux control is an important part of an optimal design of induction processes and coils.
Presentation contains advanced analysis of the magnetic flux control methods, expected benefits, material selection and magnetic controller manufacturing. Case stories provide practical evidence of the magnetic control benefits.
