|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Materials Science for High-Performance Permanent Magnets
||Texture Development Mechanism in HDDR Processed Nd-Fe-B Magnet
||Tae-Hoon Kim, Jung-Goo Lee, Hae-Woong Kwon, Cheol-Woong Yang
|On-Site Speaker (Planned)
The hydrogenation-disproportionation-desorption-recombination (HDDR) process is an effective method to produce anisotropic Nd-Fe-B powders with grain refinement to single domain level. The HDDR process consists of hydrogenation of the Nd2Fe14B phase, subsequent disproportionation into NdH2, Fe2B and α-Fe, the desorption of hydrogen from the hydride, and finally, recombination to form the original Nd2Fe14B phase. Anisotropy related to texture of Nd-Fe-B powder can be controlled by careful control of processing parameters and extensive research on orientation relations between disproportionated phases and Nd2Fe14B phase has been carried to gain an understanding of texture inducement. However, no direct observation of the c-axis transition in Nd2Fe14B phase because HDDR treatment produces plenty of cracks in powder. In this study, texture memory in terms of the c-axis orientation was directly observed. The orientation of the initial Nd2Fe14B was recovered by Fe2B phase during HDDR process and the mechanism was investigated in consideration of crystallography.