METHOD FOR MANUFACTURING R-T-B BASED SINTERED MAGNET

文件类型：PDF文档
文件大小：247K
PROBLEM TO BE SOLVED : To efficiently and uniformly apply a layer of powder particles including a heavy rare earth element RH to the surface of an R-T-B based sintered magnet without waste. SOLUTION : A method for manufacturing an R-T-B based sintered magnet comprises the steps of : preparing an R-T-B based sintered magnet (R is a rare earth element, and T is Fe or a combination of Fe and Co); preparing diffusion source powder formed from powder of an alloy or compound of a heavy rare earth element RH which is at least one of Dy and Tb; applying a sticker of a thickness of 10 μm or more and 100 μm or less to a coating area of a surface of the magnet; depositing diffusion source powder to the coating area of the magnet surface, to which the sticker has been applied, according to any of a fluidized bed coating method and a sprinkling method; and performing a thermal treatment on the magnet with the diffusion source powder deposited thereon to cause a heavy rare earth element RH to diffuse from the magnet surface inward. In the method, 90 mass% or more of a total quantity of the diffusion source powder is accounted for by powder of over 38 μm in particle size. SELECTED DRAWING : Figure 1C COPYRIGHT : (C)2019, JPO&INPIT