材料期刊网

Sm1-xFe7+x (0 less than or equal to x less than or equal to 0.9) alloys were induction-melted and rapidly quenched at various wheel velocities of 20-50 m/s. The results of X-ray diffraction show that for the composition of 0 less than or equal to x less than or equal to 0.1 the rhombohedral Th2Zn17-type structure is the main phase, and for the composition of 0.2 less than or equal to x less than or equal to 0.9 the hexagonal TbCu7-type structure is formed. AC initial susceptibility experiments indicate that at annealing temperatures below 580 degrees C the amorphous phase is crystallized to the TbCu7-type phase, while annealing up to 800 degrees C the TbCu7-type phase is transformed to the Th2Zn17 phase. After nitrogenation, the optimal condition for the best magnetic properties is obtained in Sm12.5Fe87.5Ny, quenched at 50 m/s and annealed at 700 degrees C for 30 min, and consequently nitrogenated at 460 degrees C for 4 h. The best result for the coercivity H-i(c) of the Sm12.5Fe87.5Ny achieved is 18.9 kA/cm (23.7 kOe).