不同的烧结工艺对Sm-Co2:17型高温磁体性能的影响

采用中频感应熔炼法制备了Sm(Co0.79Fe0.09Cu0.085Zr0.032)7.95合金,采用传统烧结工艺,在1200～1240℃烧结1 h,1165～1190℃固溶处理3 h,快速风冷淬火后在840℃保温12 h,以0.4℃.min-1的冷速冷却至420℃,保温10 h,最后随炉冷却。磁体经过加工后,采用不同的磁性测试手段对磁体进行测试。结果表明,磁体的剩磁随烧结温度的升高而增大,矫顽力最好的工艺为1230℃烧结1 h,然后在1180℃固溶3 h。将此工艺制备的磁体采用中国计量科学院NIM-500C超高温永磁测量仪测试,磁体在773 K时的最大磁能积为10.94 MGOe,高于已经报道的同Z值的2∶17型永磁体。磁体的磁滞回线通过振动样品磁强计(VSM)测得,室温下Br=10.5 kGs,Hcj=30.21 kOe,(BH)max=25.60MGOe;773 K时磁体Br=7.45 kGs,Hcj=6.02 kOe,(BH)max=9.85 MGOe。剩磁温度系数α=-0.0624%.℃-1,矫顽力温度系数β=-0.169%.℃-1。

Effect of Different Sintering Process on Magnetic Properties and Microstructures of 2:17-type Sm-Co High-Temperature Magnet

Sm(Co0.79Fe0.09Cu0.085Zr0.032)7.95 magnet was prepared by induction melting and traditional sintering method.The magnet was sintered at 1200~1240 ℃ for 1 h and taken the solution treatment at 1165~1190 ℃ for 3 h.The magnet was aged for 12 h at 840 ℃,slowly cooled by 0.4 ℃·min-1 to 420 ℃ and then held for 10 h.The remanence of the magnet increased as sintering temperature increases and the coercivity reached the maximum when the magnet was sintered at 1230 ℃ and solution at 1180 ℃ for 3 h.The magnet was tested by super-high temperature permanent measure instrument in national institute of metrology,and the(BH)max of the magnet is 10.94 MGOe at 773 K,which was higher than reported others magnets owning the same z value.Meanwhile,the hysteresis loops of the magnet tested by VSM showed that the magnet had a Br of 10.5 kGs,Hcj of 30.21 kOe and(BH)max of 25.60 MGOe at room temperature,and the magnet had the high temperature magnetic properties of Br=7.45 kGs,Hcj=6.02 kOe and(BH)max=9.85 MGOe at 773 K.The temperature coefficient of remanence was α=-0.0624%·℃-1 and the temperature coefficient of coercivity was β=-0.169%·℃-1 in a range of RT to 773 K.