Abstract To satisfy the application of different environments, grain boundary doping is commonly used in the preparation of sintered magnets to improve the coercivity and the corrosion resistance. In this paper, the alloys were prepared by mixing different ratios of the master alloy (Ce,Pr,Nd)-Fe-B and the sintering aid (Pr,Nd)-Al. The coercivity of sintered (Ce,Pr,Nd)-Fe-B magnet is substantially enhanced by doping 2 wt% of (Pr,Nd)-Al, while the maximum energy product decreased slightly. We have systematically investigated the corrosion behavior and microstructure of the sintered magnets in order to determine the mechanism of the degradation. The sintered (Ce,Pr,Nd)-Fe-B magnets with 2 wt% of (Pr,Nd)-Al addition exhibits the decreasing corrosion rate when comparing with others, due to the distribution of intergranular phases. The electrode potential difference between the main phase and the RE-rich phase is reduced by the addition of Al, improving the potential and stability of RE-rich phase due to the higher electrode potential of Al than that of Nd, Pr or Ce. In addition, the element distribution of the magnets doped by (Pr,Nd)-Al indicates that the Al-rich shell formed at the marginal area of the Ce-rich phase improves its stability. Therefore, intergranular adding ternary (Pr,Nd)-Al alloy powders results in both high coercivity and good corrosion resistance synchronously.

中文翻译：

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晶界三元合金掺杂对(Ce,Pr,Nd)-Fe-B永磁体耐蚀性的影响☆

摘要 为满足不同环境的应用，在烧结磁体的制备中普遍采用晶界掺杂来提高矫顽力和抗腐蚀性能。在本文中，通过混合不同比例的中间合金 (Ce,Pr,Nd)-Fe-B 和烧结助剂 (Pr,Nd)-Al 制备合金。通过掺杂2wt%的(Pr,Nd)-Al，烧结(Ce,Pr,Nd)-Fe-B磁体的矫顽力显着提高，而最大能积略有下降。我们系统地研究了烧结磁体的腐蚀行为和微观结构，以确定退化的机制。由于晶间相的分布，添加 2 wt% (Pr,Nd)-Al 的烧结 (Ce,Pr,Nd)-Fe-B 磁铁与其他磁铁相比，其腐蚀速率降低。Al的加入降低了主相和富RE相之间的电极电位差，由于Al的电极电位高于Nd、Pr或Ce，提高了富RE相的电位和稳定性。此外，(Pr,Nd)-Al 掺杂磁体的元素分布表明，在富铈相的边缘区域形成的富铝壳提高了其稳定性。因此，晶间添加三元 (Pr,Nd)-Al 合金粉末同时具有高矫顽力和良好的耐腐蚀性能。Nd)-Al 表明在富铈相的边缘区域形成的富铝壳提高了其稳定性。因此，晶间添加三元 (Pr,Nd)-Al 合金粉末同时具有高矫顽力和良好的耐腐蚀性能。Nd)-Al 表明在富铈相的边缘区域形成的富铝壳提高了其稳定性。因此，晶间添加三元 (Pr,Nd)-Al 合金粉末同时具有高矫顽力和良好的耐腐蚀性能。