Simultaneous enhancement of coercivity and electric resistivity of Nd-Fe-B magnets by Pr-Tb-Al-Cu synergistic grain boundary diffusion toward high-temperature motor rotors  

作　　者：Jiayi He Jinwen Hu Bang Zhou Haoyang Jia Xiaolian Liu Zhenhua Zhang Lin Wen Lizhong Zhao Hongya Yu Xichun Zhong Xuefeng Zhang Zhongwu Liu 

机构地区：[1]School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510640, China [2]Institute of Advanced Magnetic Materials, Hangzhou Dianzi University, Hangzhou, 310012, China

出　　处：《Journal of Materials Science & Technology》2023年第23期54-64,共11页材料科学技术（英文版）

基　　金：financially supported by the National Natu-ral Science Foundation of China(Nos.U21A205251774146,and 52171175);Jiangxi Provincial Key Science and Technology R&D Project(No.20203ABC28W006);Natural Science Founda-tion of Zhejiang Province(No.LY20E010002,2021C01023,and 2021C01033).

摘　　要：To high-power permanent magnetic motors,it is critical for Nd-Fe-B magnets to maintain the desirable coercivity at high-temperature operating conditions.To address this,two approaches have been proven effective:(1)enhancing the room temperature coercivity;(2)reducing the eddy current loss.However,these two items are difficult to be simultaneously achieved.Here,the grain boundary diffusion(GBD)of the Pr-Tb-Al-Cu-based source is applied to enhance the coercivity and electric resistivity at room temperature from 1101 kA m-1 and 2.13×10–6Ωm to 1917 kA m-1 and 2.60×10–6Ωm,and those at 120°C from 384 kA m-1 and 4.31×10–6Ωm to 783 kA m-1 and 4.86×10–6Ωm,respectively.Such optimization is ascribed to the improved formation depth of Tb-rich 2:14:1 shells with large magnetocrystalline anisotropy and the increased intergranular Pr-based oxides with high electric resistivity,induced by the coordination effects of Tb and Pr,as proven by the atomic-scale observations and the first principles calculations.It thus results in the simultaneously improved output power and energy efficiency of the motor because of the combination of magnetic thermal stability enhancement and eddy current loss reduction,as theoretically confirmed by electromagnetic simulation.

关 键 词：ND-FE-B Grain boundary diffusion COERCIVITY Electrical resistivity Eddy current loss 

分 类 号：TG111.6[金属学及工艺—物理冶金]