Modeling of evolution of growing coating composition

This paper discusses the role of coupling effects between transfer processes, chemical reactions and deformations in the evolution of phase composition of a growing coating and in the formation of a transition zone between coating and substrate. The proposed model of the coating growth is based on the equations of irreversible thermodynamics and accounts for coupling physical and chemical phenomena: diffusion, thermal diffusion, chemical reactions, elastic fields in the diffusion zone and stresses induced by diffusion. The transfer coefficients and kinetic parameters are calculated using classical theories or identified from experiments. As a result, we developed a theory that has direct practical applications and can be specified for a variety of technological and experimental situations. The formulated problem is solved numerically. The phase composition of the coating and residual stresses in the diffusion zone are obtained as a function of time under various technological conditions. The results can be used for prognosis and technology optimization.