Investigating the Impact of PVD Process Parameters on Residual Stress Distribution: A Multiscale Numerical Analysis Approach

Abstract Residual stress in thin PVD coatings arises from a combination of growth stress and thermal stress. Despite the lower processing temperature, thermal mismatch stresses can be significant due to variations in physio-thermal properties between the coating and substrate materials. Understanding the underlying physics of the deposition process and resulting stresses, particularly thermal stresses within the coating-substrate system, is paramount. Key physical parameters of both the coating and the substrate, such as coefficient of thermal expansion and elastic modulus, significantly influence thermal stresses. There is a demand for a comprehensive methodology in thermo-mechanical design, specifically for layered coatings, that should complement experimental procedures used to evaluate coating performance. Although analytical models can handle linear-elastic or simple elastic-plastic materials for thermal stress prediction, numerical techniques such as finite element analysis (FEA) can address more general 2D or 3D problems in simulating thermal stresses within coating-substrate systems. This study employs a multi-scale numerical approach to estimate the residual stress distribution within the coating-substrate system. Validation of the numerical model is conducted against experimental findings concerning a TiB2 - Tungsten Carbide coating-substrate configuration. The validated model is then utilized to explore the influence of process parameters on residual stress distribution across various coating-substrate systems.