Method of manufacturing rare-earth magnet powder, and method of manufacturing rare-earth bond magnet

Abstract

A method of manufacturing rare-earth magnet powder having excellent magnetic properties, and a method of manufacturing a rare-earth bond magnet are provided. A nitriding step is performed, in which when nitrided rare-earth magnet powder is produced, rare-earth-element/transition metal-based alloy powder is irradiated with a microwave at an atmosphere containing nitrogen atoms, so that the nitrogen atoms are allowed to enter into a crystal lattice.

1 . A method of manufacturing rare-earth magnet powder, comprising:
 providing rare-earth-element/transition metal-based alloy powder, and   nitriding the powder by irradiating a microwave in an atmosphere containing nitrogen atoms, whereby the nitrogen atoms are enter into a crystal lattice.   
     
     
         2 . The method of manufacturing rare-earth magnet powder according to  claim 1 :
 further comprising homogenizing after the nitriding step and the rare-earth magnet powder is heated in an inert gas.   
     
     
         3 . The method of manufacturing rare-earth magnet powder according to  claim 1 :
 wherein the frequency of the microwave is 1 GHz to 30 GHz.   
     
     
         4 . The method of manufacturing rare-earth magnet powder according to  claim 1 :
 wherein the average grain diameter of the powder is 2 μm to 90 μm.   
     
     
         5 . The method of manufacturing rare-earth magnet powder according to  claim 1 :
 wherein the pressure of an atmospheric gas containing nitrogen is 0.1 MPa to 5 MPa.   
     
     
         6 . The method of manufacturing rare-earth magnet powder according to  claim 1 :
 wherein the alloy powder is heated to a temperature in range of 250° C. to 600° C. in the nitriding step.   
     
     
         7 . A method of manufacturing a rare-earth bond magnet:
 wherein the rare-earth magnet powder according to  claim 1  is mixed with a resin binder or a metal binder for molding.