Phase formation during annealing as-milled powders of molybdenum disilicide

Molybdenum disilicide was synthesized by mechanical alloying (MA) technique through the elemental powder mixtures. Both α-MoSi 2 and β-MoSi 2 phases are created at the beginning stage; the final products of the mechanical alloying are β-MoSi 2 phase and amorphous state substance when milled for 96 h. The study also extended to determine the effect of the milling time on the kinetics of the phase transformation during annealing at low temperature. Mo 5 Si 3 is formed and the phase transformation of α-MoSi 2 to β-MoSi 2 occurred during the annealing at 800 °C, meanwhile, the crystallite size of α-MoSi 2 grows up obviously. MoSi 0.65 is formed during annealing for the powders milled for 48 and 96 h, which suggests that MoSi 0.65 phase is the predominant phase prior to the MoSi 2 during the crystallization of the amorphous substance. The main reaction of the powders milled for 48 and 96 h and annealed at 800 °C is the crystallization of the amorphous substance and a trace mounts of the phase transformation of β-MoSi 2 to α-MoSi 2 .