Effect of Nb doping on microstructure and magnetic properties of hot-deformed Nd-Fe-B magnets with Nd-Cu eutectic diffusion  

作　　者：Tingting Song Xin Li Xu Tang Wenzong Yin Yang Luo Dunbo Yu Wenlong Yan Jinyun Ju Renjie Chen Aru Yan 

机构地区：[1]School of Marine Engineering Equipment,Zhejiang Ocean University,Zhoushan 316022,China [2]CAS Key Laboratory of Magnetic Materials and Devices,Ningbo Institute of Material Technology and Engineering,Chinese Academy of Sciences,Ningbo 315201,China [3]Grirem Advanced Materials Co.,Ltd.,Beijing 100049,China

出　　处：《Journal of Materials Science & Technology》2022年第27期121-127,共7页材料科学技术（英文版）

基　　金：supported by the Major Project of“Science and Technology Innovation 2025 in Ningbo City(Nos.2020Z064,2019B10093);the Basic research expenses for provincial universities of Zhejiang Ocean University(No.2019J00036);the Talent introduction research fund of Zhejiang Ocean University(Nos.xjrcyj201801,11045091021)。

摘　　要：To restrict grain growth in coarse grain regions caused by the diffusion of Nd-Cu eutectic alloys,the Nb element was introduced into the precursor alloy to regulate the microstructure of melt-spun powder and die-upset magnets.The magnetic properties and thermal stability of die-upset magnets were appreciably improved through the addition of Nb.For the Nb-doped diffusion die-upset magnet,the grains inside the ribbons were refined and the coarse non-oriented surface crystallite got suppressed on the interface of ribbons during the hot-deformation process to form the anisotropic magnet.Moreover,Nd gathers at the intergranular phases,which is considered to enforce domain wall pinning force.The Nb-modified microstructure is advantageous to thermal stability and coercivity enhancement.High-resolution transmission electron microscopy images revealed that the Nb element gathered on the grain boundary and triple grain boundary to form c-Nb and h-Nb Fe B to hinder the grain growth during the hot-deformation process,which led to direct enhancement in the coercivity.Furthermore,the c-Nb and h-Nb Fe B are nonmagnetic phases that strengthened the magnetic isolation.However,the h-Nb Fe B precipitated from the hard magnetic phase and formed crystal defects which led to remanence deterioration.

关 键 词：ND-FE-B Hot deformation DIFFUSION Nb-doping COERCIVITY 

分 类 号：TG113[金属学及工艺—物理冶金]