Cold-Working and Annealing of L10-Ordering Iron-Palladium Base Intermetallics

Alloys based on FePd in the vicinity of the equiatomic composition are good model systems to study the microstructrual and phase transformation behavior of the class of technologically interesting ferromagnetic L10-intermetallics that includes also FePt and CoPt. Here, thermo-mechanical processing, involving cold-work and annealing at temperatures below the ordering temperature was used to control microstructures and to improve properties of FePd. L10- ordered FePd with ultra-fine grain sizes and up to about 8-fold increased coercivity compared with conventionally processed material has been obtained. Relationships between processing condition, microstructure (scale, morphology and texture) and the magnetic properties are discussed.