铌和锆对(Nd,Pr)_2Fe_(14)B/α-Fe快淬合金晶化和磁性能的影响  

Influences of Niobium and Zirconium Additions on Crystallization Behaviors and Magnetic Properties of Melt-Spun (Nd,Pr)_2Fe_(14)B/α-Fe Alloys

作　　者：王晨[1] 张文勇[1] 严密[1] 

机构地区：[1]浙江大学硅材料国家重点实验室,浙江杭州310027

出　　处：《中国稀土学报》2005年第3期307-311,共5页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金(50471041)

摘　　要：研究了Nb和Zr添加对快淬纳米双相(Nd,Pr)2Fe14B/α-Fe合金晶化行为和磁性能的影响。结果表明:(Nd0.4Pr0.6)8.5Fe85.5B6合金非晶晶化时,在α-Fe相初始晶化后,出现了(Nd,Pr)3Fe62B14亚稳相,最终亚稳相分解形成(Nd,Pr)2Fe14B和α-Fe两相组织;(Nd0.4Pr0.6)8.5Fe84.5Nb0.5Zr0.5B6非晶晶化时,同时析出α-Fe相和(Nd,Pr)2Fe14B相。这说明添加Nb和Zr可避免亚稳相的形成并细化晶粒,最大磁能积(BH)max从复合添加前的107.5上升到143.6kJ·m-3。而且,Nb和Zr原子在非晶晶化过程中可以部分取代Nd和Pr的晶位,使稀土原子可以参与形成更多的硬磁相,进一步提高了内禀矫顽力iHc。合金(Nd0.4Pr0.6)8.5Fe84.5Zr0.5Nb0.5B6经690℃退火10min后磁性能最优,Br=1.10T,iHc=534.2kA·m-1,(BH)max=143.6kJ·m-3。Effects of Nb and Zr substitutions on the crystallization behaviors and magnetic properties of melt-spun (Nd,Pr)2Fe 14 B/α-Fe alloys were studied. The results show that for (Nd 0.4 Pr 0.6 ) 8.5 Fe 85.5 B6 ribbons, the metastable (Nd,Pr)3Fe 62 B 14 precipitates after the initial crystallization of α-Fe and decomposes into the final mixture of (Nd,Pr)2Fe 14 B and α-Fe. For (Nd 0.4 Pr 0.6 ) 8.5 Fe 84.5 Zr 0.5 Nb 0.5 B6 ribbons, however, (Nd,Pr)2Fe 14 B and α-Fe phases precipitate simultaneously. This indicates that both Nb and Zr doping can avoid the formation of metastable phase and refine the grains, resulting in the increase of maximum energy product from 107.5 kJ·m -3 for the (Nb,Zr)-free sample to 143.6 kJ·m -3 for the (Nb,Zr)-doping samples. In the crystallization process, partial Nb and Zr atoms enter the 2∶14∶1 matrix and occupy the rare earth sites, which leads to the increase of the content of the hard magnetic phase and the further increase of the intrinsic coercivity. The optimal magnetic properties, Br=1.10 T, iHc=534.2 kA·m -1 , (BH) max =143.6 kJ·m -3 , can be achieved in the (Nd 0.4 Pr 0.6 ) 8.5 Fe 84.5 Zr 0.5 Nb 0.5 B6 ribbons annealed at 690 ℃ for 10 min.

关 键 词：钕铁硼 纳米双相 快淬 晶化 稀土 

分 类 号：TM273[一般工业技术—材料科学与工程] TG146[电气工程—电工理论与新技术]