Self-sustaining metal-sulfur reactions induced by ball milling

Combination reactions between chalcogen elements and metals are probably the most widely studied mechanically induced self-sustaining reactions (MSR). A series of five papers by Chakurov and his collaborators in the 1980s [1, 6-9] represents the first results on MSR. More recently, we performed detailed investigations on the Sn-Zn-S system [10, 12]. Those efforts resulted in hundreds of ignition time data, which exhibit systematic variation as a function of composition and milling conditions. It was shown that the degree of mechanical activation can be characterized by the mechanical dose received by the powder charge. Whether a reaction can become self-sustaining or not depends primarily on its thermodynamic properties, such as the adiabatic temperature. The ignition time, however, is more sensitive to the hardness of the reactants. The effect of inert additives is discussed, again contrasting thermodynamic and kinetic factors. The mutual suppression of ignition in mixtures of binary systems that show MSR by themselves is described.