|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Materials Science for High-Performance Permanent Magnets
||Magnetic Anisotropy and Crystallographic Alignment in d-HDDR Process of Nd-Fe-B-Ga-Nb Powders
||Takashi Horikawa, Masashi Matsuura, Satoshi Sugimoto, Masao Yamazaki, Chisato Mishima
|On-Site Speaker (Planned)
It is well known that by applying the dynamic-hydrogen disproportionation desorption recombination (<I>d</I>-HDDR) process to Nd-Fe-B magnet powders with an adequate hydrogen pressure, the resultant powders exhibit a high magnetic anisotropy owing to the crystallographic alignment of the recombined Nd<SUB>2</SUB>Fe<SUB>14</SUB>B grains. To understand the details of the alignment states during <I>d</I>-HDDR process, effects of treatment conditions on the crystallographic orientation were investigated. A characteristic orientation relationship between Fe and NdH<SUB>2</SUB> grains was observed and it was suggested that this relationship was related to a microstructure of samples after the HD stage. The difference in the hydrogen pressure during the HD stage may result in the variation of such a microstructure and the resultant size of divisions in "local texture" in which the recombined Nd<SUB>2</SUB>Fe<SUB>14</SUB>B grains are highly aligned. This work was supported by the Future Pioneering Projects/Development of Magnetic Material Technology for High-Efficiency Motors from NEDO, Japan.