Innovations in Soft Magnetic

Composites and their Applications

in Induction Systems

Dr. V. Nemkov, Dr. N. Vyshinskaya, R.T. Ruffini

R. Goldstein, C. Yakey

Overview

• SMC for magnetic flux control in induction systems

• Properties of Fluxtrol materials

• Application technique for:

- Formable materials

- Solid materials

• Coating

• Impregnation

• Machining

Coil for axle hardening

with magnetic controller

Materials for Flux Control

Fluxtrol Inc. produces 3 primary materials and 5 new

Primary products:

• Fluxtrol A

• Fluxtrol 50

• Ferrotron 559 H

New products:

• Alphaform LF, MF and HF

• Fluxtrol 100 (instead of Fluxtrol A)

• Fluxtrol LF (Low Frequency) Remelting of plasma

coated layer on a shaft

Parameters of Primary Materials

Properties Units Ferrotron

559H Fluxtrol 50 Fluxtrol A

Density ± 2% g/cm3 5.9 6.1 6.6

Initial

Permeability - 16 36 63

Maximum

Permeability - 18 55 120

Saturation

Flux Density Tesla 1 1.5 1.6

Frequency Range kHz 10-3000 10-1000 1-50

Temp. Resistance

Long Term

Short Term

Celsius 250 250 250

300 300 300

Thermal

Conductivity W/cmK 0.04 0.06 0.2

Resistivity kOhmcm >15 0.5 0.5

Parameters of New Materials Properties Units

Fluxtrol

100

Fluxtrol

LF

Alphaform

LF MF HF

Density

± 2% g/cm3 6.9 6.7 4.1 4.0 3.9

Initial

Permeability -- 80 80 11 9.8 8.8

Maximum

Permeability -- 130 165 13 10 9

Saturation

Flux Density Tesla 1.6 1.8 1.0 1.0 1.0

Frequency

Range kHz 0.05 - 50 0.05 - 3 1 - 80

10 -

450

20 -

3000

Temperature

Resistance Celsius 200 200 225 225 225

Thermal

Conductivity W/cm K 0.23 0.22 0.02 0.02 0.02

Resistivity kOhmcm 12.5 0.004 >15 >15 >15

Alphaform Materials

• Developed by Alpha One on the

basis of magnetic particles with

a thermal-curing epoxy binder

• Material is formable when warm

• Can be used for quick & efficient

installation to coils with low

tolerances

• Three versions are available:

for high (HF), middle (MF)

and low (LF) frequencies

Tin packages with formable material

Alphaform Application

• Main applications:

- Small ID and complex geometry coils

- Coils with odd turn surfaces (e.g. round tubes)

- “In-house” made coils

- Concentrator repair

• Permeability:

Alphaform LF - 12

Alphaform MF - 10

Alphaform HF - 8

• High electrical resistance

• Electrical strength is 250 Vm/mm

Alphaform Application for ID

Coils

Material easily fills internal

volumes providing good heat

transfer to water-cooled turns

Bare inductor Inductor with Alphaform MF

Heating steel pipe; same power settings; t = 6.0 sec

BARE ALPHAFORM

Fluxtrol 100

Fluxtrol 100 created to

substitute Fluxtrol A

Advantages:

• Fluxtrol 100 has lower

anisotropy and its

performance is less

dependent on cutting

direction

• Higher thermal

conductivity

• Higher mechanical

strength

0

20

40

60

80

100

120

140

0 50 100 150 200 250 300

Fl.100 reg.

Fl. 100 perp.

Fl. A reg.

Fl. A perp.

P

erm

eab

ilit

y

Permeability vs. Field Strength

Field Strength, A/cm

Fluxtrol 100 Application

Induction coils for rotational hardening of crankshafts. Concentrators are segmented to tolerate better the copper

extension during thermal cycles

Water-Cooled Magnetic Templates

• With internal water cooling Fluxtrol controllers may be

used in hot environment

• Computer simulation and experiments confirmed that

water-cooled templates carrying high magnetic field can

work in close proximity to the hot body

Water-cooled

template

Dimensions 32.7 x 88 x 222 mm (1.3 x 3.5 x 8.75”)

ELECTRICAL VARNISHES

Corrosion protection

Varnishes, paints & coatings

Electrical insulation

Varnishes, ceramic & nylon coating

Clean room requirements

Teflon coating

Aseptic (FDA standards)

Teflon coating

Material Coatings

CERAMIC COATING PTFE COATING

VARNISH COATING

Teflon Coating

Teflon coating thickness can vary from several microns to 20 microns depending on coating type and technology

Impregnation

• Impregnation consists in parts soaking in a special epoxy resin under vacuum

• Then resin penetrates into the open pores under applied pressure

• Resin polymerizes inside the pores

• Excess of resin is being removed from the surface

Impregnation Results • Better mechanical properties and

machinability

• Lower surface and volumetric corrosion

• Excellent gluing of all the surfaces

• Magnetic properties don’t change

• Increase of electrical resistivity

• Depth of penetration depends upon the material type; e.g. for

Fluxtrol 50 it is app. 0.4”

Two impregnated samples glued with epoxy 50-3100 Light areas – impregnated

layer

Sample of Fluxtrol 100 with Stainless Steel Inserts for Bolts M5

Close view of steel insert

Inserts have been screwed into the material

Fluxtrol Machining

FLUXTROL 100 DETAILS MADE W/ STRD MILL TOOLS

• Materials may be easily machined (drilled, milled, turned, ground, etc.).

• It is not necessary to use cooling or lubricating fluids.

• Use sharp carbide tools (carbide tools recommended)

• Use high spindle speed and slow feed rate (e.g., < 30”/min)

• Make pilot holes when drilling large bores.

• Use proper measures to evacuate dust and remove chips.

DETAIL W/ 1 MM WALL THICKNESS

Example: CNC Groove Machining

Waterjet Cutting

1” THICK FLUXTROL 100 LOGO CUT WITH WATERJET TECHNOLOGY

Waterjet is very effective for cutting flat profiles

Summary • Soft Magnetic Composites proved to be effective

materials for magnetic flux control in different induction

systems due to ability to work in 3D fields, excellent

machinability, good thermal conductivity and magnetic

permeability sufficient for majority applications

• Different Fluxtrol materials cover the whole range of

frequencies used in induction technique from 50 Hz up to

13.56 MHz

• Additional treatment of stock material or finished parts

allow to use magnetic controllers in special and

challenging environment

• More information about materials and their application

may be found on site www.fluxtrol.com

1388 Atlantic Blvd., Auburn Hills, MI, 48326 Ph. +1 248 393 2000, Fax +1 248 393 0277