摘要
采用放电等离子烧结技术制备了新型NdFeB磁体,研究了NdFeB磁体在湿热环境下的氧化行为和在电解质溶液中的电化学特性.在扫描电子显微镜下分析了磁体的显微组织结构和成分.结果表明,与传统烧结NdFeB磁体相比,新型磁体的显微组织特征为;主相Nd_2Fe_(14)B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.这种组织结构有效抑制了磁体沿富钕相发生的晶间腐蚀的过程,使磁体具有良好的耐腐蚀性能。
Anisotropic NdFeB magnet was prepared by spark plasma sintering(SPS) technique. Magnet with same composition was produced using conventional sintering method for comparison. The electrochemical properties in electrolytes and reaction kinetics in oxidizing environments of the magnets were studied. The microstructures and compositions of the magnets were observed with scanning electron microscope and energy dispersive X-ray detector. Compared with conventional sintered NdFeB magnet, the SPS processed magnet has an original microstructure, i.e. the grain size of the Nd2Fe14B 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 corrosion propagation are restricted and the inter-granular corrosion process is suppressed effectively. As a result, the SPS NdFeB magnet possesses an excellent corrosion resistance.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2004年第2期167-170,共4页
Chinese Journal of Materials Research
基金
国家自然科学基金50201001
50371002
北京市教委科技发展计划Km200310005019
北京市科技新星计划2003B03
关键词
材料失效与保护
耐腐蚀性
放电等离子烧结
NDFEB磁体
Composition
Corrosion resistance
Electrochemical corrosion
Microstructure
Oxidation
Reaction kinetics
Sintering
