DyF_(3)对三明治结构热变形NdFeB磁体温度稳定性和耐腐蚀性能的影响  

Effect of DyF_(3) on temperature stability and corrosion resistance ofsandwich structure hot-deformed NdFeB magnets

作　　者：黄宜平 剧锦云 陈仁杰 宋婷婷 HUANG Yiping;JU Jinyun;CHEN Renjie;SONG Tingting(School of Marine Engineering Equipment,Zhejiang Ocean University,Zhoushan 316022,China;CISRI&NIMTE Joint Innovation Center for Rare Earth Permanent Magnets,Ningbo Institute ofMaterial Technology and Engineering,Chinese Academy of Science,Ningbo 315201,China)

机构地区：[1]浙江海洋大学海洋工程装备学院,浙江舟山316022 [2]中国科学院宁波材料技术与工程研究所稀土永磁材料联合创新中心,浙江宁波315201

出　　处：《功能材料》2024年第1期1098-1102,1110,共6页Journal of Functional Materials

基　　金：国家重点研发计划项目(2022YFB3503403);宁波市自然科学基金(2023J343);贺州市中央引导地方科技发展专项资金项目(贺科ZY2022002)。

摘　　要：为了提高热变形NdFeB磁体的热稳定性和耐腐蚀性能,设计了一种添加DyF_(3)的三明治结构热变形磁体。通过对磁体上下端添加不同含量DyF_(3)粉末,调控磁体上下端晶界相的相组成、结构及成分,提高磁体的耐腐蚀性能,另一方面Dy元素部分扩散进入主相,形成了(Nd,Dy)_(2)Fe_(14)B相提高磁体磁晶各向异性场,优化热变形磁体的温度稳定性。利用脉冲磁场磁强计测试三明治结构热变形磁体的磁性能,得到高达2.16 T的矫顽力。利用电化学工作站测试三明治结构热变形磁体的极化曲线,其腐蚀电流速率较基体降低一个数量极。失重实验测试168 h后,近表面添加5%(质量分数)DyF_(3)的三明治结构热变形磁体单位表面积失重(0.061 mg·cm^(-2))远低于基体单位表面积失重(1.172 mg·cm^(-2))。微观结构分析表明,富Nd相和F元素、O元素和Dy元素分别生成NdF_(3)和Dy_(2)O_(3)化合物。XRD分析表明三明治结构热变形磁体上下端添加DyF3后织构会变差。该研究为提高热变形NdFeB磁体的温度稳定性和耐腐蚀性提供了一个新思路。In order to improve the temperature stability and corrosion resistance of hot-deformed NdFeB magnets,a sandwich structure magnet with DyF_(3) additives was designed.By adding different contents of DyF_(3) powders to the upper and lower near-ends of the magnet,the phase composition,structure and composition of the grain boundary phase in the upper and lower near-ends of the magnet were regulated,and the corrosion resistance of the magnet was improved.On the other hand,Dy element partially diffused into the main phase,forming(Nd,Dy)_(2)Fe_(14)B phase to improve the magnetocrystalline anisotropy field of the magnet and optimize the temperature stability.The magnetic properties of the sandwich structure hot-deformed magnet were measured by PFM,and the coercivity up to 2.16T was obtained.The polarization curve of the sandwich structure hot-deformed magnet was measured by an electrochemical workstation.The corrosion current rate was one order magnitude smaller than that of the substrate.For the sandwich structure magnet,the near-ends with 5wt% DyF_(3) addition showed a much smaller weight loss per unit surface area(0.061mg/cm^(2))compared with the matrix surface(1.172 mg/cm^(2))after a 168-hour PCT test.The microstructure analysis showed that NdF_(3) and Dy_(2)O_(3) compounds were formed by Nd-rich phase and F,O and Dy elements,respectively.XRD analysis showed that the texture of sandwich structure hot-deformed magnet was deteriorated after DyF_(3) addition.This study provides a new way to improve the temperature stability and corrosion resistance of hot-deformed NdFeB magnet.

关 键 词：三明治结构 热变形NdFeB 耐腐蚀性能 温度稳定性 

分 类 号：TB304[一般工业技术—材料科学与工程] TM273[电气工程—电工理论与新技术]