Combustion-wave propagation and phase-formation mechanism in the “molybdenum–carbon–active additive” system

The combustion of a mixture of molybdenum and carbon activated by a high-energy magnesium–fluoroplastic mixture was studied. The adiabatic combustion temperature and the equilibrium compositions of the combustion products were calculated and, experimental dependences of the combustion temperature and rate on the main parameters of the process are obtained. It is shown that the activation of the formation of molybdenum carbides is of a thermal nature. The two observed mechanisms of formation of molybdenum carbides are found to differ in combustion temperature: at $T<2470$ K, formation of carbides proceeds by a diffusion mechanism, and at $T>2470$ K it proceeds by crystallization from a melt. The possibility of synthesis of single-phase $\mathrm{Mo}_2\mathrm{C}$ in the combustion regime is shown.