Chemical Stresses at Composite Synthesis from Ti–Al–Fe–Fe2O3 Powder Mixture

Sintering of a heterogeneous multicomponent system in pure form cannot be attributed to either solid-phase or liquid-phase sintering. In this case, the mechanism and stages of phase formation during the sintering largely depend on the mutual arrangement of powders of different types, their shape, surface properties, temperature, etc. This leads to a variety of mechanisms for the formation of accompanying mechanical stresses. In the present work, the stresses and strains associated with diffusion and formation of new phases are highlighted in the defining relations. For the Ti–Al–Fe–Fe–Fe2O3 system, a model of reaction diffusion is presented, considering the formation of Al2O3 particles and intermetallic compounds of the Ti–Al and Fe–Al systems. Considering the obtained analytical solution, which gives an idea of the dynamics of changes in the volumes occupied by phases, the stresses in the local volume are estimated based on the solution of the mechanical equilibrium problem. Theoretical provisions qualitatively agree with the regularities observed experimentally.