Hard magnetic properties of Sm-Fe-C based alloys prepared by mechanical alloying

The structure and magnetic properties of SmyFe(100-1.5)yC(0.5y)(y=8 similar to 20) alloys prepared by mechanical alloying (MA) from Sm, Fe and graphit e have been investigated systematically. In order to improve hard magnetic properties of the alloys prepared by mechanical alloying, a new method cons isting of re-milling and re-annealing was developed. After being re-milled and re-annealed, the Curie temperature T-C of the Sm-Fe-C alloys changes. T he T-C of 2:17 phase increases, whereas the T-C of 2:14:1 phase decreases. After being re-annealed at low temperatures, the grain sizes of hard phases are smaller than those in the alloys annealed at high temperatures. The ef fects of Co or Ti substitution for Fe are studied.