放电等离子烧结具有优异综合性能的新型NdFeB永磁材料

采用放电等离子烧结技术和传统烧结技术制备了烧结NdFeB永磁体,并研究了2种磁体的磁性能、力学性能和化学稳定性.与传统烧结磁体相比,放电等离子烧结磁体具有与其相当的磁性能及更好的耐腐蚀和力学性能.显微组织结果表明,放电等离子烧结磁体主相Nd₂Fe₁₄B的晶粒细小、均匀.边界富钕相仅有少量位于主相Nd₂Fe₁₄B颗粒周围,大部分以颗粒形式分布在主相三角晶界处,这种独特的显微组织特征对于晶间腐蚀过程及脆性沿晶断裂过程具有明显的抑制作用.因此,放电等离子烧结磁体表现出优异的综合性能.

Spark Plasma Sintering Nd-Fe-B Permanent Magnets with Good All-around Property

In present study,sintered Nd-Fe-B permanent magnets with different compositions were fabricated by using both Spark Plasma Sintering(SPS)technique and conventional sintering technique.Magnetic prop- erties,mechanical properties,and chemical stabilities of the two kinds of Nd-Fe-B magnets are investigated. Compared with the conventional sintered magnets,SPS Nd-Fe-B magnets possess comparable magnetic prop- erties,better corrosion resistance and mechanical properties.Microstructure observation shows that SPS mag- net possesses unique microstructure due to the special sintering mechanism of SPS technique.In detail,the grain size of Nd_2Fe_(14)B main phase is fine and uniform,only a few Nd-rich phase forms along the grain bound- aries of Nd_2Fe_(14)B,whi1le most of them agglomerates into the triple junctions.Such mizrostructure modifica- tion restrains effectively the inter-granular corrosion and inter-granular fracture along Nd-rich phase in the SPS magnet.As a result,SPS magnets display better corrosion resistance and mechanical properties.