The electrothermal gun is a relatively new technology that produces various types of plasma vapor using high current pulsed power. A dense metal vapor plasma at extremely high temperature and high velocity is discharged from the electrothermal Molybdenum disilicide has been recognized as an attractive candidate material for high temperature structural applications. In this study, we have used mechanical alloying by a high-energy ball milling process to produce alloy powders of α-MoSi2 starting from mixtures of elemental molybdenum and silicon powders at room temperature. The α-MoSi2 plus Mo phases have been obtained by ball milling of a Mo33Si67 mixture of the pure elements for 100 hours, which was transformed to a single α-MoSi2 phase by subsequent heat treatment up to 725 oC. The grain size of the α-MoSi2 powders thus obtained was 19 nm, being approximately four times smaller than that of commercial alloy powders. It was also seen that the α-MoSi2 phase once formed begins to transform to the high-temperature β-MoSi2 phase when the total milling time exceeds 160 hours.

Keywords: Mechanical alloying (MA), Nanocrystalline α-MoSi2 compound, High-temperature structural material, Hall plot, Differential scanning calorimetry (DSC)