Fabrication of Cu-Ti-Zr based amorphous alloys by mechanical alloying

Cu40Ti60-xZrx (x = 0,10,30,50) amorphous alloys were fabricated successfully by using mechanical alloying method. The mechanism of amorphization was discussed by investigating the transformation of Cu-Ti-Zr alloy powders from crystallization to amorphous state in the process of mechanical alloying. The thermal stability and crystalline phase of amorphous alloys were also investigated. It is shown that the amorphous is formed from the original elements directly, and no metallic compounds appear in the solid-state reaction. The amorphization mechanism may be explained by the vacancy diffusion model. The DSC traces of fully amorphous Cu40TixZry powders show that the onset crystallization temperature (Tx) is increased with the decrease of Ti content and the increase of Zr content. The Cu40Ti30Zr30 and Cu40Ti10Zr50 amorphous alloys were annealed near the onset crystallization temperature, Tx. It is found that Zr2Cu, Cu4Ti and a little unidentified crystal phases were precipitated in the Cu40Ti10Zr50 amorphous alloy after annealed for 15 min, whereas there were no precipitates in the Cu40Ti30Zr30 amorphous alloy.