Mathematical modeling of metallochemical reactions in a two-species reacting disperse mixture

A heterogeneous model of gasless combustion of binary disperse systems is proposed. The model combines the description of microscale processes of interphase interaction in the cell of the mixture with the macroscale description, which allows physicochemical transformations to be described on the basis of the continuum approach of mechanics of continuous media and the phase composition of the final products to be calculated. Schemes of metallochemical reactions of formation and decomposition of intermetallic phases are proposed, based on an analysis of the state diagram of the Ni–Al system. A problem of SHS wave propagation and evolution of the spatial distribution of concentrations of intermetallic phases during combustion of a mixture of Ni and Al powders is solved numerically. A two-wave structure of the combustion wave is obtained, and comparisons with experimental data are performed.