Structure,nitridation efficiency and magnetic properties of SmFe powders and its nitrides  

作　　者：Xiao-Xia Chen Yang Luo Zhou Hu Wen-Long Yan Ning-Tao Quan Shuo Lu Dun-Bo Yu Jia-Jun Xie 

机构地区：[1]National Engineering Research Center for Rare Earth,Grirem Advanced Materials Co.,Ltd.,Beijing,100088,China

出　　处：《Rare Metals》2023年第6期1983-1988,共6页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (No.51401028)。

摘　　要：The effect of annealing temperature(TA) at600-900℃ on structure and magnetic properties of the melt-spun Sm_(8.6)Fe_(85.9)Co_(4.3)Zr_(1.2) alloys and its nitrides was investigated.Results show that the melt-spun powder is TbCu7-type SmFe_(9) single phase.X-ray diffractometer(XRD) Rietveld refinement shows that the lattice parameter a increases,c and c/a decrease with the increase in T_(A) at600-700℃.This is due to the tendency of nitrogen entering into the 3f site(1/2,0,0) during the nitridation process,which is good for the magnetic properties.The phase transforms from TbCu7-type SmFe_(9) to Th_(2)Zn_(17)-type Sm_(2)Fe_(17) at above 800 0C.Scanning electron microscopy(SEM) images show that the amount of surface defects of melt-spun powder which are harmful for magnetic properties decreases at first and then increases as TA increases.The coercivity(H_(cj)) and maximum magnetic energy product((BH)_(max)) of its nitrides increase first and then decrease as a function of TA.And the remanence(B_(r))always shows a decrease.The optimal magnetic properties of H_(cj)=748 kA·m^(-1),B_(r)=0.92 T,(BH)_(max)=118 kJ·m^(-3) are obtained by annealing at 675℃ for 2 h and then nitriding at 460℃ for 10 h.

关 键 词：Melt-spun alloy Annealing temperature Magnetic property XRD Rietveld refinement 

分 类 号：TG132.27[一般工业技术—材料科学与工程]