Microstructure and coercivity modification of HDDR (Pr, Nd, Ce)-Fe-B magnetic powders by grain boundary diffusion with Pr-Fe-Al-Ga

摘要

? 2023 Elsevier B.V.The coercivity of HDDR (Pr, Nd, Ce)-Fe-B magnetic powders can be significantly enhanced from 3040 Oe to 7271 Oe through a unique grain boundary diffusion process known as rotating adhering diffusion, which uses Pr64Fe7Al9Ga20 as a diffusion source. Microstructural analysis revealed that the diffusion process resulted in a substantial increase in grain boundaries, as well as the formation of a Pr-rich shell in the Nd2Fe14B grains. Furthermore, the replacement of partial Nd element by Pr element in the diffusion source also caused a decrease in the thermal stability of the powders by 8.06 K. This research provides significant insight into the further development of high-performance Nd-Fe-B materials.