| 摘要 |
PURPOSE:To provide a high density, high magnetic performance magnet by using, to form a molded body, powder having grain distribution with two or more peaks, in preparation of alloy permanent magnet essentially consisting of compound with specific ratio of one or more rare earth elements R to transition metal group M which includes Co. CONSTITUTION:A permanent magnet made of alloy RMz (z=6.8-9) essentially consisting of a compound having a ratio 2:17 for one or more rare earth elements R (e.g. Sm) to transition element group M (e.g. Co) that includes Co is prepared under the following condition. A melted and heat treated ingot of alloy RMz (e.g. Sm2Co17) is roughly crushed, then finely crushed using a jet mill, etc., and the resulted powder is classified by vibrating sieve, etc. into proper classes. Then, grain distribution is formed so as to give two or more peaks, which is used to form molded body. |
