A new generation of gas atomized powder with improved levels of energy product and processability

New alloy compositions have been developed which allow commercially significant levels of hard magnetic properties (>10 MGOe) to be produced by inert gas atomization (IGA). Improvements in magnetic properties are a result of altering the quenching characteristics of the liquid melt by alloying with simultaneous additions of Ti and C. IGA of previous alloy compositions produced powders in an underquenched condition which resulted in inferior hard magnetic properties. In this new generation of IGA alloys, powders are produced in an overquenched condition which results in a nanocrystalline grain structure after crystallization. This extremely fine structure allows the development of a domain structure which is very similar to optimally quenched melt-spun ribbons. Amorphous or partially crystalline structures were verified in powder particles up to 100 /spl mu/m by magnetic, thermal, and structural experimental methods.