Microstructure and super-high coercivity of Tb-containing NdFeB magnets by diffusion with Tb metal and Pr-Al-Cu-Ga

Le résumé fourni par la source

A sintered NdFeB magnet with super-high coercivity of 46.21 kOe was successfully obtained by two-step diffusion with Tb metal and Pr-Al-Cu-Ga alloys. Tb-containing magnets with super-high coercivity were used as base magnets; coercivity increased from 35.86 to 44.51 kOe for the Tb-diffused magnet and 46.21 kOe for the magnet with Tb and Pr-Al-Cu-Ga diffusion. Microstructure analysis indicated that two-step diffusion resulted in Tb/Pr-rich double-shell structures, optimized grain boundary structure, and the enhancement of RE-rich grain boundary phases, which is the main reason for the enhancement of coercivity. The diffusion-induced variation of remanence was also discussed. This work provides insights into further breaking the coercivity limit of sintered NdFeB magnets.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.