Iron Chrome Cobalt FeCrCo Overview
Iron-Chrome-Cobalt magnets (FeCrCo) have similar properties to cast Alnico 5 but, unlike cast alnico, the FeCrCo magnets are actually reasonably malleable.
The FeCrCo magnet material is semi-hard magnetically and exists in bar, rod, wire and also as thin rolled strip.
They are a replacement for CuNiFe magnetic material (CuNiFe is not commercially available any more).
Advantages
• Malleable – FeCrCo is easier to machine than Alnico
• FeCrCo can be hot deformed
• The maximum recommended operating temperature is typically around +400 degrees C
• FeCrCo has a Hc varying typically from 50kA/m to 300kA/m. The value of Hc produced depends on the method of the final heat treatment (timescale, temperature and quench rate)
• FeCrCo usually does not require any corrosion coating
Disadvantages
• If the final heat treatment is not performed, the magnetic performance is very poor
• The strips are usually thin. Thicker sheets and plate are not really possible
• Easily demagnetised or remagnetised in a different direction
Typical Applications
• Compasses
• Hysteresis coupling applications e.g. a multi-pole permanent magnet rotor turning a FeCrCo disc by hysteresis
