论文部分内容阅读
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 micro-structure and magnetic properties of the Sm(CobalFe0.233Cu0.073Zr0.024)7.6 sintered magnets was sys-tematically 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 from 2.76 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 content 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.