Patent ID: 9589714
Date: 2017-03-07
CPC Classifications: B22D,B22F,C22C,C23C,H01F

Claim:
1. A method for manufacturing a sintered NdFeB magnet, comprising: making a starting alloy ingot by a strip-cast method in which an amount of rare-earth in a metallic state is between 12.7% and 16.0% in atomic ratio and lamellas of rare-earth rich phases are formed at an average interval controlled to be substantially the same as a target average particle size; making a powder containing particles in which fragments of the rare-earth rich phases are attached to main phase particles by grinding the starting alloy ingot so that an average particle size becomes the target average particle size; sintering the powder to make a base material of the NdFeB magnet; and performing a grain boundary diffusion process of R wherein, in the powder, a rate of main phase particles to which the fragments of the rare earth rich phases are attached is equal to or higher than 80%.