微观结构调整对烧结Nd-Fe-B永磁氧化特性和磁性能的影响  

Oxidation Behavior and Magnetic Property of Nd-Fe-B Permanent Magnets With Modified Microstructure

作　　者：刘卫强[1] 岳明[1] 王公平[2] 张东涛[1] 张久兴[1] 

机构地区：[1]北京工业大学材料科学与工程学院,北京100124 [2]江西师范大学物理与通信电子学院,南昌330022

出　　处：《北京工业大学学报》2010年第10期1408-1412,共5页Journal of Beijing University of Technology

基　　金：国家自然科学基金资助项目(50371002);高等学校博士点科研基金资助项目(20091103120024);北京工业大学博士科研启动基金资助项目(52009999200706)

摘　　要：采用放电等离子烧结技术(SPS)制备了新型Nd-Fe-B磁体,采用传统烧结工艺制备了相同成分的磁体.测量了磁体在不同温度下的氧化动力学、不可逆损失以及氧化前后磁性能的变化.利用扫描电子显微镜分析了磁体氧化前后的显微组织结构.结果表明,高温氧化后SPS磁体的磁性能损失低于传统磁体.显微组织观察表明新型磁体具有独特的显微组织特征:主相Nd2Fe14B晶粒细小、均匀;富钕相在主相晶粒边界上分布较少,主要集中在三角晶界处.这种组织结构有效地抑制了磁体沿富钕相发生晶间氧化的过程,因此磁体具有良好的耐氧化性能.Anisotropic Nd-Fe -B magnet was prepared by Spark Plasma Sintering technique. Magnet with same composition was produced using conventional sintering method for comparison. The magnetic property before and after oxidation test of both magnets were studied. The oxidation kinetics and irreversible losses of both magnets under different temperature were also investigated at the same time. The microstructures before and after oxidation test were observed with scanning electron microscope. Compared with conventional sintered Nd -Fe -B magnets,the SPS magnets process less reduction of magnetic properties after high temperature oxidation test. Microstructure observation shows that SPS magnet has original microstructure,i. e. the grain size of the Nd2Fe14 B main phase is fine and uniform,and the fine Nd-rich phase does not form along the grain boundaries of main phase,but agglomerates into the triple junctions. Therefore,the pathways for oxidtion propagation are restricted and the inter-granular oxidation process though Nd-rich phase in the magnet is suppressed effectively. As a result,the SPS Nd -Fe -B magnet possesses excellent oxidation resistance.

关 键 词：微观结构 磁性能 氧化 放电等离子烧结 ND-FE-B磁体 

分 类 号：TG178[金属学及工艺—金属表面处理] TM271.3[金属学及工艺—金属学]