Permanent magnets prepared from Sm10.5Fe88.5Zr1.0Ny without homogenization

In as-cast Sm2Fe17 the high amount of α-Fe caused by a peritectic reaction can be considerably reduced by a small addition of about 1 at% Zr. X-ray diffraction showed that as-cast Sm10.5Fe88.5Zr1.0 mainly consists of a phase with the Th2Zn17-type structure and SmFe3. Non-homogenized Sm10.5Fe88.5Zr1.0 was milled and (i) annealed in vacuum or (ii) treated with a hydrogenation-disproportionation-desorp tion-recombination (HDDR) process. The annealed and subsequently nitrogenated powder is magnetically anisotropic and has a coercivity μ0JHC up to 2.0 T and an energy product (BH)max up to 136 kJ/m3. HDDR-treated and nitrogenated powder is isotropic and exhibits values of μ0JHC = 3.1 T and (BH)max 103 kJ/m3. Consequently, Sm10.5Fe88.5Zr1.0Ny (y ∼ 16) permanent magnets with very good properties can be prepared without the time-consuming homogenization procedure. (orig.)