Model of transition zone evolution between coating and substrate under intense short thermal impulse

Abstract

In the present work a model of the evolution of the composition of the transition zone between the material and the pre-applied coating under conditions of intense short-term thermal impulse is proposed. The pulse times are assumed to be comparable to the relaxation times of the heat and mass fluxes. This led to the need to account for finite rates of heat and mass propagation in the model, leading to hyperbolic transfer equations. The phenomena of thermodiffusion (Soret effect) and diffusive thermal conductivity (Dufour effect) and some possible chemical reactions leading to a change in the transition zone composition are also taken into account. This nonlinear model problem illustrates the necessity of the really coupled problem solution to reveal the feature of cross-effects in irreversible conditions. It was found that due to the wave heating and the wave nature of the movement of elements, chemical reactions can start during the action of a short pulse outside the heating zone expected only due to thermal conductivity.