铸造/热压Pr-Fe-B磁体的矫顽力及其与晶粒尺寸关系  

COERCIVITY AND ITS GRAIN SIZE DEPENDENCE IN CAST-HOT PRESSED Pr-Fe-B MAGNETS

作　　者：陈钟敏[1] 谢发勤[1] 史正兴[1] 王乐仪[1] 傅恒志[1] 

机构地区：[1]西北工业大学

出　　处：《金属学报》1991年第5期B345-B349,共5页Acta Metallurgica Sinica

基　　金：中科院物理所磁学开放实验室的部分资助

摘　　要：研究了铸造/热压 r_(19)Fe_(74.5)B_5Cu_(1.5)永磁体的磁硬化特点.发现磁体反磁化过程受反向畴的形核控制.矫顽力与晶粒尺寸的对数存在线性关系: _iH_c(MA/m)=1.7312—0.4816Ind(μm)根据反向畴形核的随机性和矫顽力的统计特性讨论了该式的物理意义。Characteristics of magnetic hardening in cast-hot pressed magnet Pr_(19)Fe_(74.5)B_5Cu_(1.5) were studied. The microstructure features and virgin magnetization curve reveal a nucleation controlled coercivity mechanism. Regression analysis shows that the intrinsic coercivity varies inversely as the logarithm of the average grain size: _iH_c(MA/m)=1.7312-0.4816lnd(μm) which confirms the randomness of nucleation of reversed domains and the statistical nature of coercivity, indicating that the decrease of grain size would reduce the average number of defects on its surface and lower the probability of magnetization reversal of a grain and the cumulative fraction of the grains that have reversed their magnetization. Coercivity is thus enhanced.

关 键 词：铸造 热压 稀土 永磁体 矫顽力 

分 类 号：TG21[金属学及工艺—铸造]