A self-propagating high-temperature synthesis process of the TiC reactive system was numerically simulated to investigate the effect of porosity and diluent on the SHS reaction and its activating mechanism by an implicit difference method (IDM) and a Gauss-Seidel iteration procedure. The new features of the model include a consideration of the melting of each constituent of the reactants and product and the inclusion of considerations involving dilution and porosity. The results show that as the porosity is varied, there is not a significant effect on the combustion temperature and mode of the combustion front, and the nature of the combustion front is steady and uniform because of the lower activation energy in this system. As the reactant porosity values are decreased, the combustion velocity first increases because of an increase in the thermal conductivity. The combustion velocity, after reaching a maximum, decreases with a further decrease in the porosity because of the high value of the thermal conductivity of the reactants. To study the effect of the diluent, the product itself is considered as the diluent. The effect of adding the diluent to the initial reactants is to decrease the combustion temperature and the combustion velocity.

Keywords: Self-propagating high-temperature synthesis, Combustion temperature, Propagation velocity, TiC system.