Coupled Model of Coating Formation on a Cylindrical Substrate
S. A. Shanin1, A. G. Knyazeva1,2
1Tomsk Polytechnic University, Tomsk, 634004 Russia
2Institute of Strength Physics and Materials Science, Tomsk, 634021 Russia
Keywords: coating deposition, cross effects, chemical transformations, coupled model
Abstract
A coupled model of coating formation on the surface of a part of a cylindrical shape during deposition from the plasma is proposed. This model takes into account the phenomena of thermal diffusion, diffusive thermal conductivity, and mass transfer under the action of the stress gradient, and the formation of chemical compounds. The coating growth rate is considered to be a given function of the particle velocity and particle concentration near the surface of the growing coating. The problem is solved numerically. It is shown that diffusion cross-fluxes, diffusive thermal conductivity, and thermal diffusion during the growth process reduce the width of the transition zone between the substrate and the coating. This effect becomes most essential if the substrate has a low thermal conductivity. Accounting for stresses arising in the coating-substrate system during the deposition process changes the effective transfer coefficients and significantly affects the result of modeling the distribution of chemical elements and their compounds in the coating.
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