粉末烧结钕铁硼激光熔凝层的易磁化轴取向

研究当各向异性粉末烧结Nd15Fe77B8永磁体的磁化方向分别与x,y,z轴平行时,其上激光熔凝层中Nd2Fe14B胞柱晶的易磁化轴的取向特征.采用XRD,SEM,Bitter粉纹等实验方法对粉末烧结Nd15Fe77B8永磁体表面的激光熔凝层进行了分析.结果表明:当磁体的磁化方向分别与x,y轴平行时,其上激光熔凝层中Nd2Fe14B胞柱晶的易磁化轴具有与粉末烧结基体相同的取向;而当磁体的磁化方向与z轴平行时,其上激光熔凝层中的Nd2Fe14B胞柱晶的易磁化轴在xoy平面内随机分布.在激光快速熔凝条件下,磁体表面激光熔凝层中的胞状Nd2Fe14B的择优生长方向为100]晶向.

Arrangement of easy magnetization axis of cellular column Nd2Fe14B in laser melting/solidification pool on sintered Nd15Fe77B8 magnets

The arrangements of the easy magnetization axis 001] of cellular Nd_2Fe_(14)B of the cellular column zone in the laser melting/solidification pool, were investigated by XRD, SEM, and the Bitter method, on sintered Nd_(15)-(Fe_(77)B_8) magnets. The results show that the cellular columns of Nd_2Fe_(14)B at the zone are straight and parallel to z-axis. If the magnetization direction of the magnets is originally parallel to x, y-axis respectively, the cellular Nd_2Fe_(14)-B of the zone in the laser melting/solidification pool has the same arrangement of the easy magnetization axis as the magnets. But if the magnetization direction of the magnets is originally parallel to z-axis, the easy magnetization axis of the cellular Nd_2Fe_(14)B at the zone is in the xoy plane. And the preferential growth direction of all the cellular Nd_2Fe_(14)B in the laser melting/solidification pool is 100] under the condition of laser rapid solidification.