Abstract Interface reactions and structure of Pr52.5Tb17.5Cu30, Pr60Tb20Al20 and Pr60Tb10Cu15Al15 (at%) alloys with Nd-Fe-B magnets processed at various temperatures were systematically investigated. The alloys first melted and diffused through grain boundaries, and a higher temperature was required to form Tb-rich shells. Compared to Pr52.5Tb17.5Cu30 and Pr60Tb20Al20, Pr60Tb10Cu15Al15 with Al/Cu co-doping promoted Tb diffusion through grain boundaries especially at a lower temperature than 800 °C, and consequently developed continuous and thin Tb-rich grain boundaries. We presented two-step diffusion process with Pr60Tb10Cu15Al15, including low-temperature diffusion to accelerate Tb diffusion through grain boundaries and subsequent high-temperature diffusion to mainly promote Tb grain diffusion. Consequently, due to more homogeneous Tb distribution and resulting thinner Tb-rich grain boundaries, coercivity increment of 11 kOe was achieved by introducing only 0.33 wt% Tb, obviously lower than 0.48 wt% in conventional one-step diffusion magnet.

中文翻译：

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Pr-Tb-Cu-Al合金/Nd-Fe-B磁体界面反应和Tb扩散行为的温度依赖性

摘要 系统研究了 Pr52.5Tb17.5Cu30、Pr60Tb20Al20 和 Pr60Tb10Cu15Al15 (at%) 合金与 Nd-Fe-B 磁体在不同温度下的界面反应和结构。合金首先熔化并通过晶界扩散，形成富含 Tb 的壳需要更高的温度。与 Pr52.5Tb17.5Cu30 和 Pr60Tb20Al20 相比，具有 Al/Cu 共掺杂的 Pr60Tb10Cu15Al15 促进了 Tb 通过晶界的扩散，尤其是在低于 800 °C 的温度下，从而形成了连续且薄的富 Tb 晶界。我们提出了 Pr60Tb10Cu15Al15 的两步扩散过程，包括低温扩散以加速 Tb 通过晶界的扩散和随后的高温扩散以促进 Tb 晶粒扩散。最后，