Rare-earth alloy powders for magnets and process for making magnets from rare-earth alloy powders

摘要

A process for passivating rare-earth alloy powders such that magnets formed from the powders have fewer expansion defects is described. By exposing the rare-earth alloy powders to a humid atmosphere, rare-earth oxide impurities that could result in eruptions in the magnets are reduced. Magnets made from the passivated powder show fewer expansion defects than magnets made from unpassivated powder.