热处理对放电等离子烧结NdFeB永磁材料的影响

Effect of heat treatment on NdFeB permanent magnetic material prepared by spark plasma sintering

摘要: 采用放电等离子烧结技术(spark plasma sintering,简称SPS)制备了高性能新型NdFeB永磁材料。研究了热处理工艺对SPS NdFeB磁体的组织和性能影响,采用扫描电镜、B-H回线仪研究磁体的显微组织和磁性能。结果表明,不同烧结温度的SPS烧结体对不同温度的热处理表现出同样的规律性,最佳热处理温度为1050℃。SPS NdFeB磁体的热处理过程,富稀土相成分和结构发生改变。在优化工艺条件下制备出最佳性能为B_r=1.351T,H_ci=674.4kA.m^-1,BH_m=360.4 kJ.m^-3的新型SPS NdFeB磁体。

Abstract: A new type of NdFeB magnets with high magnetic properties was prepared by spark plasma sintering（SPS）technique.Effect of the heat treatment conditions on microstructure,magnetic properties and metallurgical transformations of magnets was systematically studied,by means of SEM,B-H loop-line instrument,and XRD,respectively.It is found that the SPS NdFeB magnets sintered at different temperatures during heat treatment exhibit and there exists an optimum temperature of 1050℃.The coercivity of SPS NdFeB magnets increases,owing to changing of structure and composition of Nd-rich phase during heat treatment.Under optimum processing conditions,the SPS NdFeB magnet possesses the best magnetic properties with a remanence of 1.351T,a coercive force of 674.4 kA·m^-1,and a maximum energy product of 360.4 kJ·m^-3