Optimization of both coercivity and knee-point magnetic field of Sm2Co17-type magnets via solid solution process  

作　　者：Shuai Wang Yikun Fang Kuikui Song Xiaoyu Zhu Lei Wang Wei Sun Wei Pan Minggang Zhu Wei Li 

机构地区：[1]Division of Functional Materials Research,Central Iron and Steel Research Institute,Beijing 100081,China [2]National Engineering Research Center for Magnetic Materials,Beijing 102600,China

出　　处：《Journal of Rare Earths》2020年第11期1224-1230,I0003,共8页稀土学报（英文版）

基　　金：Project supported by the National Key Research and Development Program of China(2016YFB0700903);the National Natural Science Foundation of China(51590882;51401054)。

摘　　要：It is confirmed that phase homogenization is very important for improving the magnetic properties of 2:17-type Sm-Co sintered magnets,In this work,the influence of solid solution process on microstructure and magnetic properties of the Sm(CobalFe0.233Cu0.073Zr0.024)7.6 sintered magnets was systematically studied.With the solid-solution treating duration(tS)increasing from 0 to 4 h,intrinsic coercivity(Hcj)increases from 12.83 to 36.54 kOe,magnetic field at knee-point(Hknee)increases from2.76 to 19.14 kOe,and the maximum energy product increases from 19.79 to 29.48 MGOe.The electron probe microanalyzer results reveal that there mainly exist gray and dark regions besides"white"rare earth-rich phase,and the conte nt of Sm,Fe and Cu elements for the two kinds of regions changes a lot for the specimens,Furthermore,with tS increasing up to 4 h,the elements content deviation between the gray and dark regions becomes small gradually from 3.94 at%to 0.27 at%,7.66 at%to 0.21 at%and 7.27 at%to 0.16 at%for Sm,Fe and Cu elements,respectively.Moreover,transmission electron microscopy results show that the distribution of cell size is much more concentrated for aged specimens when tS is 4 h.It is also found that the Cu concentration at cell boundaries for the 4 h solid-solution treatment case shows relatively higher values and greater concentration gradient(1.94 at%/nm).It is verified that sufficient solution treatment duration is prerequisite to form these homogeneous microstructural features,which are the key points for obtaining both high Hcj and Hknee.

关 键 词：Sm-Co magnets Solid solution process COERCIVITY Microstructure Cell size Rare earths 

分 类 号：TG146.45[一般工业技术—材料科学与工程] TG156.94[金属学及工艺—金属材料]