Patent ID: 9728311
Date: 2017-08-08
CPC Classifications: B22F,C22C,H01F

Claim:
1. A method for preparing a Neodymium-Iron-Boron (Nd—Fe—B) based sintered magnet, the method comprising: 1) providing a master alloy and an auxiliary alloy, the master alloy being a Nd—Fe—B alloy ingot or cast strip, the auxiliary alloy being a heavy rare earth alloy having a formula of R 2) breaking up the master alloy using a hydrogen decrepitation process to yield a crude powder, conducting hydrogen absorption treatment on the auxiliary alloy and breaking up the hydrogenated auxiliary alloy to yield hydride particles; 3) uniformly mixing and stirring the crude powder of the master alloy and the hydride particles of the auxiliary alloy to yield a mixture, wherein a weight percentage of the crude powder of the master alloy is greater than or equal to 75% and less than 100% of a total weight of the mixture, and a weight percentage of the hydride particles of the auxiliary alloy is greater than 0 and less than or equal to 25% of a total weight of the mixture; 4) milling the mixture obtained in step 3) to yield powders having a surface area mean diameter of between 1 and 5 μm; 5) uniformly stirring the powders obtained in step 4) and conducting orientation forming treatment on the powders, to yield a raw body of a Nd—Fe—B based magnet; and 6) sintering the raw body of the Nd—Fe—B based magnet.