Nd_(70)Al_(30)晶界调控对烧结钕铁硼重稀土扩散的影响  

Effect of Nd_(70)Al_(30)Grain Boundary Modified on Heavy Rare Earth Diffusion in Sintered NdFeB

作　　者：刘路军[1] 刘政[2] 刘仁辉[3] 刘永 LIU Lu-jun;LIU Zheng;LIU Ren-hui;LIU Yong(Faculty of Materials Metallurgy and Chemistry,Jiangxi University of Science and Technology,Ganzhou 341000,China;Jiangxi University of Science and Technology,Ganzhou 341000,China;Jiangxi Key Laboratory for Rare Earth Magnetic Material and Devices,Jiangxi University of Science and Technology,Ganzhou 341000,China)

机构地区：[1]江西理工大学材料与冶金学部,江西赣州341000 [2]江西理工大学,江西赣州341000 [3]江西理工大学稀土磁性材料及器件研究所,江西赣州341000

出　　处：《稀土》2024年第4期89-96,共8页Chinese Rare Earths

基　　金：国家重点研发计划(2020YFB1713700)。

摘　　要：采用晶界调控的方法制备了(PrNd)_(30)Fe_(69-x)B_(1)M_(x+y)Nd_(70)Al_(30)(y=0、0.25%、0.50%、0.75%、1.00%,质量分数)扩散前驱体,利用磁性能测量仪(NIM20000)、电子探针X射线衍射分析仪(EPMA)、透射电镜(TEM)研究了晶界调控合金Nd_(70)Al_(30)含量改变对晶界扩散磁体矫顽力的影响。结果表明:随着Nd_(70)Al_(30)添加量的提高,无论是平行于C轴还是垂直于C轴的晶界扩散,磁体矫顽力都显著提高。当Nd_(70)Al_(30)合金添加量为1.00%时,磁体的矫顽力达到1800 kA/m左右,矫顽力各向异性得到显著改善。EPMA显微组织分析表明:经晶界调控后可以有效减少垂直于C轴扩散时Tb元素的表面富集,在深入磁体芯部区域形成了连续的富Tb壳层结构,富Tb壳层和晶界相中Fe元素含量相对降低。经TEM分析,晶界调控后垂直于C轴扩散的磁体晶间形成界面平直、薄且连续的富Nd相,隔离了主相间的磁耦合,大幅提高了磁体的矫顽力。(PrNd)_(30)Fe_(69-x)B_(1)M_(x+y)Nd_(70)Al_(30)(y=0、0.25%、0.50%、0.75%、1.00%)diffusion precursors were prepared by the grain boundary modified method.The effect of the grain boundary modified alloy Nd_(70)Al_(30)content on the coercivity by grain boundary diffusion was studied by BH tracer(NIM20000),EPMA,and Transmission Electron Microscope(TEM).The results showed that with the addition of Nd_(70)Al_(30),the coercivity of the magnet increased significantly,whether it diffused parallel or perpendicular to the C axis.When the addition of the Nd_(70)Al_(30)alloy is 1.00%,the coercivity of the magnets reaches about 1800 kA/m,and the anisotropy of coercivity is significantly improved.The microstructure results showed that the grain boundary modification effectively reduced the enrichment of Tb element when diffusing applied perpendicular to the c-axis,and formed a continuous Tb-rich shell structure in the magnet deeply.The Fe element in grain boundary phase and Tb-rich shell were lower relatively reduced.After grain boundary modification,the flat,thin,and continuous Nd-rich phase was formed between the grain along the vertical TEM analysis showed that C-axis diffusion magnets,which isolated the demagnetization coupling between the two main phases and greatly improved the coercivity of the magnets.

关 键 词：钕铁硼 晶界扩散 矫顽力 晶界调控 各向异性 

分 类 号：TM273[一般工业技术—材料科学与工程]