High-coercivity Nd-Fe-B Powders Obtained by High-Temperature Milling

Abstract The possibility of employing high temperature milling (600°C) for the production of highly coercive Nd-Fe-B powders was examined. The materials were the Nd 12 Fe 82 B 6 , alloy which was subjected to mechanical milling and the powders of the constituent elements of this alloy which were processed by mechanical alloying. The processes were conducted in the two variants: the first variant consisted of mechanical milling performed at a high temperature which was maintained during the entire process, and the other variant included preliminary milling carried out at room temperature and then the milling temperature was increased. All the processes gave nanocrystalline powders with hard magnetic properties. The powders produced by mechanical milling had better properties than those produced by mechanical] alloying as they were more homogeneous and contained smaller amounts of the α-Fe phase.