Hard Magnetic Sm2-Fe17-Nx Compound by Mechanical Alloying
YOUNG-SOON KWON1, JIN-SOO MOON1, MYUNG-JIN SUK2 and CHUNG-HYO LEE3
1Research Center for Machine Parts and Materials Processing, University of Ulsan,
Ulsan 680-749 (South Korea)
E-mail: yskwon@mail.ulsan.ac.kr
2Dept. of Metallurgical Engineering, Samchok National University,
Samchok 245-080 (South Korea)
3Dept. of Advanced Materials Science & Engineering, Mokpo National University,
Muan 534-729 (South Korea)
Страницы: 99-102
Аннотация
In the present work, mechanical alloying technique was applied to prepare hard magnetic Sm2Fe17Nx powders. Starting from pure Fe and Sm powders, the formation process of hard magnetic Sm2Fe17Nx phase by mechanical alloying and subsequent solid-gas reaction was studied. At as milled condition powders were found to consist of Sm-Fe amorphous and a-Fe phases in all compositions of SmxFe100-x (x = 11, 13, 15, 17). The effects of starting composition on the formation of Sm2Fe17 intermetallic compound was investigated by heat treatment of mechanically alloyed powders. When Sm content was 15 at. %, heat-treated powders consisted of nearly Sm2Fe17 single phase. For preparation of hard magnetic Sm2Fe17Nx powders, additional nitriding treatment was performed under N2 gas flow at 450 °C. The increase in the coercivity was proportional to the nitrogen content, which increased drastically at first and then increased gradually as the nitriding time was extended to 3 h.
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