2:17型稀土钴永磁体磁饱和度对其不可逆损失的影响

Influence of degree of magnetization saturation on the irreversible loss of 2:17-type rare earth cobalt permanent magnets

采用亥姆霍兹线圈测试不同磁饱和度及工作点(P_c)的2:17型钐钴磁体温度老化前后的磁通,计算经温度老化后的不可逆损失,探讨了老化温度、永磁体磁饱和度及P_c对其不可逆损失的影响。结果表明,永磁体的不可逆损失随老化温度的升高、磁体磁饱和度的降低及P_c的降低而变大。不可逆损失绝对值小于1%时,老化温度为200℃,P_c=0.27的磁体磁饱和度需要超过53.6%,而P_c=1.78仅需超过31.5%,老化温度为300℃,P_c=0.27的磁体的磁饱和度需要超过88.6%,而P_c=1.78的磁体仅需超过68.1%。

In this paper, the magnetic flux of 2：17-type Sm-Co magnets was tested in different degree of magnetic saturation and working point （Pc） by Helmholtz coil meter before and after aging, and their irreversible loss after temperature aging calculated. The influence of aging temperature, degree of magnetic saturation and working point on the irreversible loss was discussed. The results show that the irreversible loss of the magnet increases with increasing aging temperature, decreasing degree of magnetic saturation and working point. For the irreversible loss absolute value of less than 1% and the aging temperature of 200℃, the magnetic saturation of magnet of Pc =0.27 require to be over 53.6%, while that of Pc =1.78 only require to exceed 31.5%; for the irreversible loss absolute value of less than 1% and the aging temperature of 300℃, the magnetic saturation of magnet with Pc =0.27 require to be over 88.6%, while that of Pc =1.78 only require to exceed 68.1%.