Adiabatic thermal explosion in disperse condensed systems with limited solubility of the reactants in the product layer

A mathematical model of the self-heating of dispersed solid mixtures is considered taking into account the boundary kinetics of formation of the intermediate product phase. It is shown that decreasing the ratio of the characteristic diffusion time to the characteristic reaction time can lead to a transition from the diffusion regime to the kinetic regime, resulting in a change in the effective activation energy of the synthesis and the growth pattern of the product layer. This change may be due to decreases in the heterogeneity scale of the mixture and the ratio of the activation energy of the formation of the new phase to the activation energy of diffusion. An analytical model of the solid-state reaction in the kinetic regime was developed and used to obtain temperature dependences of the coordinates and velocities of the boundaries of the growing layer.