Effect of milling time on the microstructure and magnetic properties of amorphous Ti50Fe50 alloys prepared by mechanical alloying

The effect of milling time on the microstructural evolution and magnetic properties of Ti50Fe50 alloys prepared by mechanical alloying were investigated. The results showed that the powder size was decreased sharply and then stabilized. Correspondingly, the milled powders experienced a transition from the lamellar shape to the spherical shape due to severe plastic deformation as well as the competition of cold welding and fracturing when the milling time was increased. Compared with the detailed composition primary powder (composed of Ti and α-Fe phases), the nanocrystalline Ti and α-Fe phase gradually disappeared and the amorphous phase were formed in the Ti50Fe50 alloys after milling for 40 h. When the milling time was increased to 60–90 h, the nanocrystalline disappeared and the complete amorphization of the milled Ti50Fe50 alloys occurred. However, a small amount of the nanocrystalline TiFe was formed except for a large of amorphous phase in Ti50Fe50 alloys for 100 h. Meanwhile, the formation of paramagnetic amorphous/nanocrystalline Ti and TiFe phase resulted in the saturation magnetization and coercive of the milled Ti50Fe50 alloys were decreased. Therefore, they exhibited excellent soft magnetic (0–90 h) and paramagnetic properties (100 h).