Further enhancing the coercivity of Nd-Tb-Fe-B sintered magnets by Dy grain boundary diffusion

Autor: Fu Song, Juhua Xie, Hiroshi Nagata, Jiaying Jin, Mi Yan
Rok vydání: 2021
Předmět:
Zdroj: Materials Letters. 283:128718
ISSN: 0167-577X
DOI: 10.1016/j.matlet.2020.128718
Popis: The coercivity of Nd–Fe–B sintered magnets was progressive enhanced by Tb alloying and Dy grain boundary diffusion (GBD). Every 1 wt% Tb doping led to about 0.37 T linear increase in the coercivity. For all magnets with different Tb content after Dy GBD, the coercivity increased by about 0.7 T with the formation of network enriched with Dy. As Dy diffusion flux was determined by Dy concentration gradient, the coercivity enhancement of Dy GBD was not affected by the Tb content of base magnets. Dy enriched at the TJs diffused along the grain boundary with the Nd-rich phase extending along the grain boundary during post diffusion annealing process. Similar with post sintering annealing, the coercivity increased by about 0.3 T after post diffusion annealing. Therefore, alloying and diffusing different heavy rare earth elements was an effective way to prepare Nd-Fe-B sintered magnets with higher magnetic properties.
Databáze: OpenAIRE