STUDY ON HIGH-PERFORMANCE SM2FE17NX MAGNETS

Several technological factors which affect the permanent magnetic perf ormance of Sm2Fe17Nx magnets, such as the phase composition (especiall y alpha-Fe), nitrogen and oxygen contents, as well as the ball milling speed and time, have been systematically examined. The coercivity inc reases with decreasing alpha-Fe content. Oxidation leads to decreases in the saturation magnetization and remanence. The nitrogen content de pendence of either the coercivity or remanence shows a maximum at x=3. The remanence and coercivity as functions of the ball milling time al so show maxima. Compared with high energy ball milling, low energy bal l milling is more suitable for improving the coercivity and the remane nce. Sm2Fe17Nx powder magnets with B-r=1.2 T, mu(Oi)H(c)=0.8 T and (BH )(max)=25 MGOe have been obtained.