Effect of MgCl_(2) on electrophoretic deposition of TbF_(3) powders on Nd-Fe-B sintered magnet  

作　　者：Chen Wang Yang Luo Zilong Wang Wenlong Yan Yanyan Zhao Ningtao Quan Haijun Peng Kaiwen Wu Yuehua Ma Chunlei Zhao Dunbo Yu 

机构地区：[1]National Engineering Research Center for Rare Earth,GRINM Group Co.,Ltd.,Beijing 100088,China [2]GRIREM Advanced Materials Co.,Ltd.,Beijing 100088,China [3]General Research Institute for Nonferrous Metals,Beijing 100088,China

出　　处：《Journal of Rare Earths》2023年第5期721-727,I0004,共8页稀土学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(2021YFB3500201,2021YFB3500202);the Beijing Youth Top-Notch Team Support Project of China(2018000021223TD10);the Beijing NOVA Program(Z211100002121092);the Natural Science Foundation of Hebei Province(E2021103006);the Hebei Province International Science and Technology Cooperation Base Construction Project of China(20591002D)。

摘　　要：Using electrophoretic deposition(EPD)method,the TbF_(3)powders were deposited on the surface of sintered Nd-Fe-B magnets,and the effects of MgCl_(2)on electrophoretic deposition and grain boundary diffusion were investigated.The results show that addition of 5 wt%MgCl_(2)can significantly improve the EPD efficiency and improve the adhesion of the coating by releasing local stress through the formation of special gully morphology.Combining with Biesheuvel equation,the effects of suspension concentration,voltage and time on EPD amount were studied.The Biesheuvel equation can be simplified asγ=AUSct/L,and A(=0.0141-0.0144)in this experiment was calculated to achieve the quantitative calculation of EPD amount.After heat treatment of 875℃×10 h+500℃×1 h,the coercivity of 48H(7 mm)sintered magnet with 0.3 wt%TbF_(3)increases from 18.5 to 22.4 kOe,with an increase of 21.1%.The core-shell structure was observed by a back-scattered scanning electron microscope(BSE-SEM),which proves that the addition of MgCl_(2)has no adverse effect on the grain boundary diffusion of Nd-Fe-B sintered magnets.

关 键 词：Electrophoretic deposition ND-FE-B TbF_(3) Coating adhesion Grain boundary diffusion Rare earths 

分 类 号：TG174.4[金属学及工艺—金属表面处理]