Heat and Stress State of Coated Bodies Under Dry Friction Taking into Account Radiation Heat Exchange

Abstract

With the use of developed mathematical models of thermomechanics of layered plates and a one-dimensional model of continuous frictional contact, the problem of studying the thermal and stress states of bodies with coatings under dry friction was formulated. The initial relations are obtained for a system of infinite plane-parallel layers, which consists of a moving layer to which a pressing distributed load is applied and a layer (substrate) on which the coating is applied. The system as a whole is in conditions of convective-radiative heat transfer with the external environment. Considering the coating as a thin intermediate layer (interlayer), the study of the thermal behavior of a three-layer system is reduced to the study of a two-layer system, and the effect of the coating is taken into account by generalized contact thermal conditions. At the same time, the stress state in the near-surface regions of the layers caused by heating during friction can be estimated by the obtained approximate relations, which take into account the reduced bending and tensile characteristics of the intermediate layer (coating). A numerical methodology for solving the formulated nonlinear contact-boundary value problems of heat conduction is developed, and the temperature and stress state in the system are investigated depending on the pressing load and the friction speed. Also, the initial relations for determining the temperature and stresses in a two-layer plate (coated layer) for the problem of technological heat treatment with the help of thermal radiation are obtained. At the same time, generalized boundary conditions (conditions of heat transfer through the coating) and approximate expressions for thermal stresses are obtained, taking into account the reduced bending and tensile characteristics of the coating.