Ce含量对单合金RE_(2)Fe_(14)B中磁体磁性能、微观结构和耐腐蚀性能的影响  

Magnetic Properties,Microstructure,and Corrosion Resistance of Single Alloy RE_(2)Fe_(14)B Magnets with Different Ce Content

作　　者：郭子振 刘卫强[1] 陈昊[1] 杨天元 岳明[1] 魏启锋 Guo Zizhen;Liu weiqiang;Chen Hao;Yang Tianyuan;Yue Ming;Wei Qifeng(Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124,China;Hangzhou Foresee Technology Co.,Ltd.,Hangzhou 311500,China)

机构地区：[1]北京工业大学材料与制造学部,北京100124 [2]杭州智见科技有限公司,浙江杭州311500

出　　处：《稀有金属》2024年第9期1227-1234,共8页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(52071004)资助。

摘　　要：基于单合金工艺开发高性能的含Ce烧结磁体仍然是一个瓶颈问题。此外,单一Ce含量变化对单合金含Ce烧结磁体耐腐蚀性能的影响尚不清楚。采用单合金工艺制备了Ce/TRE(TRE=total rare earth)含量分别为30%,35%和40%的3种烧结磁体,其成本与相近最大磁能积(BH)_(max)的商用N档烧结钕铁硼磁体相比降低了33.7%~41.1%,并且Ce/TRE含量为30%和35%的磁体具有与N40和N38商用烧结钕铁硼磁体相当的室温磁性能。观察了3种烧结磁体的微观结构,并在多种腐蚀条件下对磁体的耐腐蚀性能进行了研究,结果发现:随着磁体中Ce含量的增加,REFe_(2)相含量随之增多。REFe_(2)相与传统富RE相相比,Fe浓度更高,化学稳定性更好,并且REFe_(2)相成团块状聚集分布,这使得晶界相连续性变差。一方面晶界相连续性变差使矫顽力(H_(cj))降低,磁性能变差;另一方面在磁体晶界相连续性变差导致腐蚀通道受阻和REFe_(2)相的综合影响下,随Ce含量增加,烧结磁体在高压加速腐蚀环境、中性盐雾环境中以及电化学腐蚀测试条件下表现出更好的耐腐蚀性能。实验结果为解释磁体Ce含量与磁体磁性能和耐腐蚀性能间的关系提供了参考。The development of high-performance Ce-containing sintered magnets based on a single alloy process remains a bottleneck problem.In addition,the effect of Ce content variation on the corrosion resistance of single alloy Ce-containing sintered magnets is not clear.In this paper,Ce30,Ce35 and Ce40 sintered magnets containing Ce were prepared by a single alloy process,and their Ce/TRE(TRE=total rare earths)were 30%,35%and 40%,respectively.The magnetic properties of Ce30 and Ce35 magnets reached N40 and N38 grade of common commercial sintered magnets(coercivity≥955 kA·m^(-1)).Using the ratio of(BH)_(max) to the cost per kilogram the magnet as a comparison standard,the costs of the three Ce-containing sintered magnets were reduced by 33.7%~41.1%compared to those of the common commercial N grade sintered NdFeB magnets with similar(BH)_(max).The phases analysis by X-ray diffraction(XRD)and Rietveld fitting showed that the content of REFe_(2) phase increased from 4.35%for Ce30 magnets to 5.31%for Ce40 mag⁃nets with the increase of Ce substitution.The microstructures of three Ce-containing sintered magnets were observed,and it was found that the thin layers of grain boundary phases gradually became blurred and discontinuous with the increase of Ce content in the mag⁃nets.In addition,Ce elemental content in the agglomerated triangular grain boundary phases was higher than that of Nd,and there was also a higher Fe concentration.The agglomerated triangular grain boundary region with high Ce and Fe content and low Pr and Nd con⁃tent was analyzed for the elemental mass ratio,and RE/Fe atomic ratio showed that the region was REFe_(2) phase.The content and distri⁃bution state of the REFe_(2) phase produces some changed in the microstructure of the magnets,which therefore caused variations in the magnetic properties as well.The effect of the Ce content of sintered magnets on the corrosion resistance of magnets was further investi⁃gated:under the corrosion conditions of high pressure accelerated aging,the corrosion wei

关 键 词：单合金含Ce烧结磁体 磁性能 微观结构 耐腐蚀性 

分 类 号：TM273[一般工业技术—材料科学与工程]