钕铁硼磁体中镝含量对扩散磁体磁性能和温度稳定性的影响  

Influence of Dysprosium Content in Nd-Fe-B Magnets on Magnetic Properties and Temperature Stability of Diffused Magnets

作　　者：刘乔波 王志恒 刘延丰 曹俊 李仲 王舒远 朱利强 熊俊杰 LIU Qiaobo;WANG Zhiheng;LIU Yanfeng;CAO Jun;LI Zhong;WANG Shuyuan;ZHU Liqiang;XIONG Junjie(Jiangxi Copper Technology Institute Co.,Ltd.,Nanchang 330096,China;Jiangxi Copper Co.,Ltd.,Nan-chang 330096,China)

机构地区：[1]江西铜业技术研究院有限公司,江西南昌330096 [2]江西铜业股份有限公司,江西南昌330096

出　　处：《铜业工程》2024年第4期122-129,共8页Copper Engineering

基　　金：国家重点研发专项(2023YFB3507501);赣鄱俊才支持计划项目(20232BCJ23056)资助。

摘　　要：采用晶界扩散工艺制备了高性能烧结钕铁硼磁体,研究了不同镝含量(0~2%)基材对扩散后磁体性能和温度稳定性的影响。通过扫描电子显微镜(SEM)和X射线衍射仪(XRD)分析表明,晶界扩散之后重稀土元素镝进入基体主相,形成“核-壳”结构,主相边缘由Nd_(2)Fe_(14)B相变成了磁晶各向异性场更高的(Nd,Dy)_(2)Fe_(14)B硬磁相。不同镝含量基材磁体在晶界扩散后,矫顽力均有不同程度提高,不含镝的磁体基材矫顽力增幅最大,增量为7.05 kOe,而2.0%镝含量的基材矫顽力增幅最小,仅增加5.30 kOe。基材镝含量越高,扩散源中的镝元素进入磁体内部越少,矫顽力增幅越小,扩散效率越低。晶界扩散后磁体的矫顽力温度稳定性得到强化,矫顽力温度系数提高,2.0%镝含量基材扩散后在20~120℃区间的矫顽力温度系数最大,达到-0.52%/℃。In this paper,high-performance sintered Nd-Fe-B magnets were prepared by grain boundary diffusion process.The effects of different Dy contents(0~2%)on the post-diffusion magnetic properties and temperature stability of the magnets were studied.Scanning electron microscopy and X-ray diffraction analysis showed that after grain boundary diffusion,the heavy rare earth element Dy entered the main phase of the matrix,forming a"core-shell"structure.The edges of the main phase were converted from Nd2Fe14B phase to the higher magnetic anisotropy field(Nd,Dy)2Fe14B hard magnetic phase.After grain boundary diffusion,the coercivity of magnets with dif⁃ferent Dy contents in the substrate increased to different degrees.The magnets without Dy had the largest increase in coercivity,with an increment of 7.05 kOe,while the magnets with 2.0%Dy had the smallest increase in coercivity,only increasing by 5.30 kOe.With higher Dy content the less Dy element enters the magnet interior,the smaller the coercivity increase,and the lower the diffusion effi⁃ciency.The temperature stability of coercivity of the magnets after grain boundary diffusion was strengthened,and the temperature coef⁃ficient of coercivity was improved.The temperature coefficient of coercivity of the magnets with 2.0% Dy in the substrate was the larg⁃est in the 20~120℃range,reaching-0.52%/℃.

关 键 词：烧结钕铁硼 晶界扩散 重稀土 磁性能 温度稳定性 

分 类 号：TM273[一般工业技术—材料科学与工程]