EFFECT OF GASEOUS FLUID PHASES ON COMBUSTION OF METALS IN NITROGEN

The effect of gaseous fluid phases, which form in a wave of combustion during desorption of gases from solid-phase reagent, on the macrokine tic parameters of the process in systems consisting of nitrogen and Ti , Zr, Nb, and Ta metals was investigated. It is shown that, depending on the content of the sorbed gaseous impurity in the powder of the ini tial solid-phase reagent, two combustion regimes can be realized in th ese systems at low nitrogen pressures: (a) slow macrodiffusion combust ion with high content of gas desorbed in the wave of combustion and (b ) a fast kinetic regime with low content of gas desorbing in the wave of combustion. It was found that the critical parameters of the transi tion to spin combustion largely depend on the presence of a fluid gas phase in the metal powder. The nature of the appearance of the spin re gime of combustion in the metal-gas system at low gas pressures was de termined.