METHOD OF MANUFACTURING R-T-B BASED SINTERED MAGNET

PROBLEM TO BE SOLVED : To provide a method of manufacturing an R-T-B based sintered magnet with a high coercive force without using heavy rare earth elements, capable of improving a coercive force not only near the surface of a magnet but at the inside of the magnet (capable of increasing a thickness of an intergranular grain boundary) and having a coercive force improvement effect that is not largely impaired even by surface grinding for magnet size adjustment.SOLUTION : A method of manufacturing an R-T-B based sintered magnet includes the steps of : preparing an R1-T1-X (R1 is mainly Nd, T1 is mainly Fe, and X is mainly B) based alloy sintered body mainly characterized by having a molar ratio of [T1]/[X] of 13.0 or more; preparing an R2-Zn based alloy; and bringing at least a part of the R2-Zn based alloy 2 into contact with at least a part of the surface of the R1-T1-X based alloy sintered body 1 and performing heat treatment at a temperature of 450°C or above and 800°C or below.SELECTED DRAWING : Figure 2COPYRIGHT : (C)2018, JPO&INPIT