( 1. 寧波大學工程力學與材料科學系， 寧波 315211;
2. 南昌航空工業(yè)學院 材料科學與工程系， 南昌 330034)
摘 要: 研究當各向異性粉末燒結(jié)Nd15Fe77B8永磁體的磁化方向分別與x， y， z軸平行時， 其上激光熔凝層中Nd2Fe14B胞柱晶的易磁化軸的取向特征。采用XRD, SEM, Bitter粉紋等實驗方法對粉末燒結(jié)Nd15Fe77B8永磁體表面的激光熔凝層進行了分析。結(jié)果表明： 當磁體的磁化方向分別與x, y軸平行時，其上激光熔凝層中Nd2Fe14B胞柱晶的易磁化軸具有與粉末燒結(jié)基體相同的取向；而當磁體的磁化方向與/z/軸平行時，其上激光熔凝層中的Nd2Fe14B胞柱晶的易磁化軸在xoy平面內(nèi)隨機分布。 在激光快速熔凝條件下，磁體表面激光熔凝層中的胞狀Nd2Fe14B的擇優(yōu)生長方向為［100］晶向。
關(guān)鍵字: 激光表面熔凝； Nd2Fe14B；易磁化軸；晶體生長方向
cellular column Nd2Fe14B in laser melting/solidification pool on sintered Nd15Fe77B8 magnets
（ 1. Department of Engineering Mechanics and Materials Science,
Ningbo University, Ningbo 315211, China;
2. Department of Materials Science and Engineering,
Nanchang Institute of Aeronautical Technology, Nanchang 330034, China）
Abstract: The arrangements of the easy magnetization axis ［001］ of cellular Nd2Fe14B of the cellular column zone in the laser melting/solidification pool, were investigated by XRD, SEM, and the Bitter method, on sintered Nd15-Fe77B8 magnets. The results show that the cellular columns of Nd2Fe14B 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 Nd2Fe14-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 Nd2Fe14B at the zone is in the xoy plane. And the preferential growth direction of all the cellular Nd2Fe14B in the laser melting/solidification pool is ［100］ under the condition of laser rapid solidification.
Key words: laser melting/solidification; Nd2Fe14B; easy magnetization axis; crystal growth direction
