中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 14 No. 4 August 2004 |
（State Key Laboratory of Powder Metallurgy,
Central South University,Changsha 410083, China）
Abstract:Sm(CobalFe0.197Cu0.049Zr0.026)7.5 magnet with Hciof 2105 kA/m andβ18 200℃of -0.17%/℃was made by sintering processing. The magnet has uniform celluler structure. The cel, l interior is a rhombohedarl 2∶17 phase, and the boundary is a hexagonal 1∶5 phase. The average cell size is 93 nm and the cell boundary thickness is 20 nm. The cells are enriched in Fe, and the cell boundaries are enriched in Cu. More Cu-riched 1∶5 cell boundary phase would be helpful to
obtain a higher coercivity and lower temperature coefficient. White secondary phase mainly consisting of Sm can decrease the coercivity of the magnets, but the closely paralleled grooves can increase coercivity.
Key words: high temperature magnet; coercivity; cell structure; grooves
