Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5461065 | Journal of Alloys and Compounds | 2017 | 22 Pages |
Abstract
In this study, the coercivity enhancement of hot-deformed Nd-Fe-B magnet by grain boundary diffusion process (GBDP) has been studied with a new method. The mixed powders of NdHx and Cu were used as a diffusion source instead of the Nd-Cu eutectic alloy powders in order to simplify the GBDP. Before GBDP, reactions of NdHx and Cu powders were examined by XRD patterns. The Nd-Cu eutectic reaction in the mixed powders was confirmed after heat treatment at temperature higher than 550 °C. In the GBDP, the amount of diffused Nd-Cu alloy increased with increasing heat treatment temperature. However, when the same amount of Nd-Cu is diffused, the coercivity increment of the heat-treated magnet at low temperature is higher than that of the heat-treated magnet at high temperature. It is observed that higher temperature can induce grain growth and composition change of the Nd-rich grain boundary phase. The large coercivity increment of approximately 8 kOe was achieved after GBDP at 600 °C for 1 h, where the diffused Nd-Cu was 5.85 wt%.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Hee-Ryoung Cha, Kwang-Won Jeon, Ji-Hun Yu, Hae-Woong Kwon, Yang-Do Kim, Jung-Goo Lee,