Abstract The effect on the Nd-rich phase distribution of the ingot for hydrogenation-disproportionation-desorption-recombination (HDDR) powders was studied. Coercivity of HDDR powders was elevated to 1.64 T by crushing the ingot into particles and annealing at 800 °C for 18 h. HDDR processed Nd-Fe-B powders blended with Pr-Cu powders and annealed at 580 °C for 3 h were hot-pressed to obtain fully dense magnets. The microstructure evolution in hot-pressed HDDR magnets proved the impact of Pr-Cu diffusion on coercivity that the coercivity of hot-pressed magnets was improved to 1.55 T significantly. Backscatter electron microscopy and transmission electron microscopy observations revealed that the variation in coercivity owing to the diffusion of Pr-Cu along the grain boundary with heat treatment. L-TEM images illustrated the thicker grain boundary layer can pin the motion of the domain wall more effectively, resulting in a higher coercivity in HP magnets.

中文翻译：

---

使用Pr-Cu共晶合金扩散HDDR Nd-Fe-B粉末制备的热压磁体矫顽力增强

摘要 研究了加氢-歧化-解吸-复合(HDDR)粉体铸锭富Nd相分布的影响。通过将铸锭粉碎成颗粒并在 800 °C 下退火 18 小时，HDDR 粉末的矫顽力提高到 1.64 T。将 HDDR 处理的 Nd-Fe-B 粉末与 Pr-Cu 粉末混合并在 580°C 下退火 3 小时进行热压以获得完全致密的磁体。热压 HDDR 磁体的微观结构演变证明了 Pr-Cu 扩散对矫顽力的影响，热压磁体的矫顽力显着提高到 1.55 T。背散射电子显微镜和透射电子显微镜观察表明，由于热处理时 Pr-Cu 沿着晶界扩散，矫顽力发生变化。