Relationship between microstructure and magnetic domain structure of Nd--Fe--B melt-spun ribbon magnets
Masaaki TAKEZAWA(),Hiroyuki TANEDA,Yuji MORIMOTO
Department of Applied Science for Integrated System Engineering, Faculty of Engineering, Kyushu Institute of Technology, 1-1 Sensui-cho, Tobata-ku, Kitakyushu, Fukuoka 804-8550, Japan
The relation between the microstructure, observed using an electron probe microanalyzer, and the domain structure, observed using a Kerr microscope, was established to evaluate the effects of hot rolling and the addition of Ti--C on the c-axis orientation and the magnetization process of hot-rolled Nd--Fe--B--Ti--C melt-spun ribbons. The addition of Ti--C promotes the c-axis orientation and high coercivity in the ribbons. Elemental mapping suggests a uniform elemental distribution; however, an uneven distribution of Ti was observed in an enlarged grain with Ti-enriched points inside the grain. The reversal domains that nucleated at the Ti-enriched point inside the grain cause low coercivity.
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