Effect of the thermal treatment on the microstructure and magnetic property of Fe68Zr20B12 alloy prepared by mechanical alloying

Abstract

Fe68Zr20B12 amorphous alloy prepared by mechanical alloying technique of 60 h of duration was annealed at different temperatures (420-720°C) during 1 h. Microstructure and magnetic property of as-milled and annealed alloy were investigated by X-ray diffraction, transmission electron microscopy, the Mössbauer spectroscopy and vibrating sample magnetometer techniques. Fe68Zr20B12 powders milled during 60 h exhibit amorphous character. After annealing at 420°C, α-Fe phase precipitates from amorphous matrix. Transmission electron microscopy analysis shows the nucleation and growth of α-Fe grains. The Mössbauer results of the annealed alloy at 670°C show that the Fe3B phase precipitates already and there is still remaining amorphous phase. Coercivity increases with increasing annealing temperature, which is closely related to the microstructures after annealing.