A NEW-GENERATION OF GAS-ATOMIZED POWDER WITH IMPROVED LEVELS OF ENERGY PRODUCT AND PROCESSABILITY

New alloy compositions have been developed which allow commercially si gnificant levels of hard magnetic properties (>10 MGOe) to be produced by inert gas atomization (IGA). Improvements in magnetic properties a re a result of altering the quenching characteristics of the liquid me lt by alloying with simultaneous additions of Ti and C. IGA of previou s alloy compositions produced powders in an underquenched condition wh ich resulted in inferior hard magnetic properties. In this new generat ion of IGA alloys, powders are produced in an overquenched condition w hich results in a nanocrystalline grain structure after crystallizatio n. This extremely fine structure allows the development of a domain st ructure which is very similar to optimally quenched melt-spun ribbons. Amorphous or partially crystalline structures were verified in powder particles up to 100 mu m by magnetic, thermal, and structural experim ental methods.