1994 年 41 巻 11 号 p. 1331-1335
Sm2Fel7NX permanent magnet was prepared by using Sm2.0-2.5Fe17 alloy powders as the starting material, and the effect of starting composition of alloy powder on nitriding process and magnetic properties was investigated. The alloy powders were subjected to mechanically grinding (MG) in NH3 atmosphere for 10.8ks and subsequent nitriding in N2 gas flow for 3.6-10.8ks at as low temperature as 623K. X in Sm2Fe17NX was confirmed to be about 3 for all of specimens after nitriding for 7 10.8ks. Maximum coercivity, 960kA/m (12.1kOc) was observed for Sm 2.3 specimen after the above nitriding process, and even the Sm=2.0 specimen with stoichiometric composition showed the coercivity higher than 80OkA/m (10kOc).