高温2∶17型SmCo永磁体的显微组织及其与磁性能的关系

Microstructure and its relationship with magnetic properties of high temperature 2∶17 type SmCo permanent magnets

为了解2∶17型SmCo永磁体的显微组织与磁性能的关系,用粉末冶金法制备了4种Sm(CobalFe0.1-CuyZr0.04)z烧结磁体,每种成分磁体都进行了热处理工艺优化实验;并对磁体的显微组织及其与磁性能的关系进行了研究。结果表明:z值较低,同时Cu含量又较高的Sm(CobalFe0.1Cu0.16Zr0.04)6.7磁体具有最佳磁性能;扫描电镜(SEM)观察表明:显微组织表现为晶粒细小均匀且基本没有孔洞,晶界析出物均匀平滑地沿晶粒边界析出、且不成大块聚集的磁体具有较好的磁性能;磁力显微镜(MFM)观察表明:Sm(CobalFe0.1Cu0.16Zr0.04)6.7磁体的显微组织呈明显的胞状结构,磁畴结构表现为波纹畴结构,其高温磁滞回线在400℃时方形度仍较好,Hci仍有830kA/m,矫顽力温度系数(β)达-0.15%/℃,在500℃时退磁曲线才开始恶化。

With the aim of understanding the relationship between the mierostructure and property of the 2 ： 17 type SmCo permanent magnets, the high temperature permanent magnets Sm（CobalFe0.1-CuyZr0.04）z were prepared by conventional powder metallurgy method, tbe process optimization experiments of heat： treatment were done to every magnet, the microstructure and its relationship with magnetic properties have been systematically studied by using SEM, MFM, etc. The results show that The Sm（CobalFe0.1Cu0.16Zr0.04）6.7 magnet with low z and high Cu content has best magnetic properties; the magnet with fine and even microstructure, and crystal boundary separating matter deposited smoothly and evenly, and without porosity as well has the better magnetic properties; and Sm（CobalFe0.1Cu0.16Zr0.04）6.7 magnet is of cellular microstrueture and bar and wave magnetic domain structure. The 2nd quadrant demagnetization curves was good at 400 ℃ yet, β arrives at -0.150%/℃ and Hci keeps to 830 kA/m, but begin to worsen at 500℃.