R-T-B BASED PERMANENT MAGNET

文件类型：PDF文档
文件大小：663K
PROBLEM TO BE SOLVED : To provide an R-T-B based permanent magnet which has a high residual magnetic flux density and a high coercive force, and which is large in the effect of increasing the coercive force by diffusion of a heavy rare earth element at grain boundaries. SOLUTION : An R-T-B based permanent magnet comprises : R which is a rare earth element; T which represents Fe and Co; and B which is boron. The R-T-B based permanent magnet includes at least Dy as R; and M, provided that M is one or more elements selected from a group consisting of Cu, Ga, Al, Mn, Zr, Ti, Cr, Ni, Nb, Ag, Hf, Ta, W, Si, Bi and Sn. The R-T-B based permanent magnet comprises at least Cu as M. Supposing that the total mass of R, T, B and M is 100 mass%, the total content of R is 28.0-30.2 mass%, the content of Dy is 1.0-6.5 mass%, the content of Cu is 0.04-0.50 mass%, the content of Co is 0.5-3.0 mass%, and the content of B is 0.85-0.95 mass%. SELECTED DRAWING : None COPYRIGHT : (C)2019, JPO&INPIT