Effect of milling time on phase transition and grain growth during the annealing process of MA powders

The phase transition procedure of the mechanic alloy (MA) molybdenum disilicide (MoSi2) was investigated. The influences of the milling time on the phase transition induced by annealing of the MA powders milled for different time were observed also. Prolong milling time restrained the β-MoSi2 growth. The amorphous phase first transformed to the intermediate Mo silicide (MoSi0.65) during the crystallization of the amorphous substance at the annealing process. The sequence of phase transition may be MoSi(amorphous) → MoSi0.65 → β-MoSi2 → α-MoSi2. A critical crystalline size during the phase transition of β → α was observed to be approximately 20 nm in this experiment.