(西安交通大学 材料科学与工程学院，西安 710049)
摘 要: 采用热压变形法对NdFeB磁体晶间富Nd相的显微组织进行了研究。实验结果表明，NdFeB磁体经真空热压变形后，富Nd相不再平均地分布在磁体晶间，而是聚集成团块状或从磁体边缘渗出。显微组织分析表明， 富Nd相主要是由α-Nd和Nd2Fe17两相组成，与Nd-Fe合金的共晶组织成分接近。对于晶间添加Al元素的磁体，Al溶入晶间形成Nd2Fe15Al2相弥散地分布在晶界上，这有益于磁体矫顽力的提高；对于晶间添加Cu元素的磁体， 晶间没有发现有新相产生。
关键字: NdFeB磁体； 富Nd相； 晶间合金化； 磁性能
sintered NdFeB magnets after thermal extruding
（School of Materials Science and Engineering，
Xi′an Jiaotong University,Xi′an 710049， P.R.China）
Abstract:The microstructure of intergranular Nd-rich phase of sintered NdFeB magnets hasbeen studied by means of thermal extruding. After thermal extruding Nd2Fe17B7 magnets，Nd-rich phases are not distributed in the intergranular region on the average and a lot of Ndrich phases aggregate or separate from the magnet. The results show that the microstructure of Nd-rich is consisted of α-Nd phase and Nd2Fe17 phase，which approaches to eutectic structure of binary Nd-Fe alloy. After adding element Al，Nd2Fe15Al2 phases segregate near to the grain boundary of the magnetic Nd2Fe14B phase, which leads to the improvement of coercivity of magnets.
Key words: NdFeB magnets; Nd-rich phase; magnetic properties
