학술논문
Study on Microstructure and Coercivity of Thermally Processed Nd-Fe-B–type HDDR Material
Document Type
Article
Author
Source
Journal of Magnetics, 23(2), pp.274-279 Jun, 2018
Subject
Language
English
ISSN
2233-6656
1226-1750
1226-1750
Abstract
Variation of intrinsic coercivity of the HDDR-treated Nd12.5Fe80.8B6.4Ga0.3 alloy after heating in various modes was investigated. Influence of vacuum degree and cooling after heating on the coercivity of the HDDR material was examined. The heat-treated HDDR material had consistently higher coercivity when it was quenched after heating compared to when slow-cooled. Higher coercivity in the quenched material was attributable to the grain boundary with lower Fe content. HDDR-treated material heated in high vacuum showed consistently higher coercivity than the material heated in lower vacuum, and this was attributed to less heavily oxidized surface. Reduced coercivity of the HDDR-treated material heated at moderate temperature was noticeably recovered at higher temperature, and this was attributed to lower Fe content in the grain boundary.