| 摘要 |
The present invention addresses the problem of providing a method for easily producing an RFeB system sintered magnet having high coercivity and being capable of suppressing the influence of eddy current during a period of use while being composed of a plurality of unit sintered magnets strongly bonded together. It is a method for producing an RFeB system sintered magnet composed of at least two unit sintered magnets 11 bonded to each other at flat bonding surfaces, each unit sintered magnet composed of crystal grains whose main phase is made of R 2 Fe 14 B containing, as a main rare-earth element R, a light rare-earth element R L which is at least one element selected from the group of Nd and Pr. A paste 12 prepared by mixing an organic matter and a metallic powder containing at least one element selected from the heavy rare-earth elements R H of Dy, Ho and Tb is sandwiched between the mutually neighboring unit sintered magnets 11, and a grain boundary diffusion treatment is performed by performing a heating process, with the paste 12 in contact with each bonding surface. The coercivity is improved by this grain boundary diffusion treatment. Furthermore, since an oxide or similar compound of R H and/or R L is formed at the boundary of the unit sintered magnets 11, the influence of eddy current during a period of use is suppressed, and the unit sintered magnets 11 are strongly bonded together. |
