Analysis Technique for Improving Coercivity of （分析技术对提高矫顽力）.pdf

Hitachi Review Vol. 64 (2015), No. 8 493 Featured Articles Analysis Technique for Improving Coercivity of Nd-Fe-B Magnets and Development of Dy-free Magnet Hiroyuki Yamamoto, Dr. Eng. OVERVIEW: Hitachi is working to improve the performance of the Nd- Isao Kitagawa, Dr. Sc. Fe-B magnets that help make people’s way of life more energy efficient Teruo Kohashi, Dr. Sc. and reduce the load it places on the environment. To study the factors that govern coercivity, an important parameter of magnet performance, Hitachi Akira Sugawara, Dr. Eng. used a combination of advanced measurement techniques for evaluating Takeshi Nishiuchi, Dr. Eng. the magnetic properties of a magnet’s internal structure and simulation techniques for analyzing magnetization reversal behavior. This analysis found that the properties of the grain boundary phase have a strong influence on coercivity. By working on material developments that focused on the grain boundary phase, Hitachi Metals, Ltd. has commercialized the NEOMAX * Low Dy Series, a new range of Nd-Fe-B magnets developed to significantly reduce the use of Dy, a rare element. The Research Development Group at Hitachi, INTRODUCTION Ltd. is working on the research and development of SINTERED magnets