Preparation of anisotropic Nd(Fe,Mo)_(12)N_(10) magnetic materials by strip casting technique and direct nitrogenation for the strips

摘要

The Nd(Fe,Mo)_(12)-type alloys are prepared by strip casting technique, and direct nitrogenation of the strips without precrushing is executed in this paper. It is found that 6 h annealing treatment at 1050 ℃ for the strips is enough to obtain the single-phase Nd(Fe,Mo)_(12) compounds. The strips can be directly nitrogenated at 620 ℃ to obtain interstitial Nd(Fe,Mo)_(12)N_(1.0) materials, and a spontaneous pulverization phenomenon in the strips induced by nitrogenation is found. The results indicate that the nitrogenation process of the strips can be used to prepare Nd(Fe,Mo)_(12)N(1.0) interstitial nitrides and pulverize the casted strips into fine particles simultaneously. base on this, we propose a new technical route of preparing Nd(Fe,Mo)_(12)N_x magnetic powders without precrushing and obtain anisotropic NdFe_(10.5)MO_(1.5)N_(1.0)powders with a remanence of b_r=1.08 T, a coercivity of _iH_c = 400 kA/m, and a maximum energy product of (bH)_(max)= 144 kJ/m3.