Magnetically anisotropic spherical powder and method of making same

A method of forming a bonded magnet consisting essentially of magnetically anisotropic powder, said method comprising the steps of:

• forming a substantially spherical powder having a major magnetic phase and an average particle size of less than about 200 microns by inert gas atomization, said powder being comprised of at least one element from the iron group, at least one rare earth element, and boron;
• diffusing hydrogen into said substantially spherical powder at elevated temperatures in an amount sufficient to disproportionate said major magnetic phase;
• desorbing said hydrogen by heating the disproportionated powder under vacuum;
• mixing the dehydrogenated powder with a suitable binder to form a mixture comprised of powder particles dispersed in said binder;
• and
• aligning and magnetizing the powder particles in said mixture in a magnetic field.

A method of forming a magnetically anisotropic powder, said method comprising the steps of:

• forming a substantially spherical powder having a major magnetic phase and an average particle size in the range from about 10 microns to about 70 microns, said powder being comprised of at least one element from the iron group, at least one rare earth element, and boron;
• diffusing hydrogen into said powder at elevated temperatures in an amount sufficient to disproportionate said major magnetic phase to yield a disproportionated powder, the disporportionated powder maintaining the substantially spherical shape and average particle size in the range from about 10 microns to about 70 microns of the as-formed powder;
• and
• desorbing said hydrogen by heating the disporportionated powder under vacuum.