Reaction synthesis of refractory disilicides by mechanical alloying and shock reactive synthesis techniques

The reaction synthesis of disilicides of Group IVA-VIA transition metals by mechanical alloying and shock reactive synthesis techniques has been investigated. All nine disilicide compounds were directly produced from their elemental powder mixtures by mechanical alloying. Moreover, the formation of some disilicides, such as MoSi₂ and NbSi₂, proceeded by mechanically induced self-propagating reactions, the mechanism of which is analogous to that of the self-propagating high-temperature synthesis (SHS). Shock reactive synthesis of MoSi₂, NbSi₂, and TiSi₂ was conducted with a one-stage gun. Powder samples used for the shock study were prepared from metal-silicon powder mixtures that had been subjected to high-energy ball milling. The explosive driven flyer plate struck the sample-containing capsule at a velocity of 1 km s^-1. In most cases, shock-induced reactions went to completion. The effect of thermochemical driving force on the reactive formation of the disilicide compounds is discussed.