New processing routes for the preparation of Sm2Fe17Mx (M≡C and/or N) materials

Abstract Plasma carbonitriding, Zn metal coating via the chemical vapor deposition of Zn(C 2 H 5 ) 2 and high pressure sintering were studied as new processing routes to prepare Sm 2 Fe 17 M x (M ≡ C and/or N) material with good magnetic properties. Two reactions of carbiding and nitriding for Sm 2 Fe 17 simultaneously took place by glow discharges under differential pumping conditions of mixed gases in the ternary system CH 4 + N 2 + H 2 . The compound with chemical formula Sm 2 Fe 17 C > x N y ( x + y ≈ 3) was produced by a plasma reaction at 723 K, and the coercivity value was increased to around 11 kOe after the ball milling treatment up to a particle size of about 3 μm. Furthermore, the surface coating of Sm 2 Fe 17 C x N y with the Zn metal derived by the decomposition of Zn(C 2 H 5 ) 2 showed good oxidation resistivity and much more enhancement of the coercive force. The high pressure sintering of Zn/Sm 2 Fe 17 C x N y provided the magnetic molding materials free from the α-Fe phase.