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Erosion is one of the modes of material degradation that can have significant impact on service life and safety of gas turbine engines operated in dusty conditions, such as desert areas. Damage caused by eroding particles, such as sand, dust or volcanic ash, lowers engine power, decreases fuel efficiency and shortens service life. One of the most effective methods of protection against erosion is application of erosion-resistant coatings. The leading technology in the development of these coatings is Physical Vapor Deposition (PVD). Typically, the PVD coatings, such as nitrides or carbides of transition metals, are much harder than most steels or specialized alloys and have appreciably lower erosion rates. Recent research on the development of erosion-resistant coatings has been directed to the finite element modelling of the behavior of coating and substrate, and their interface under the impact of eroding particles. The approach presented in this paper is based on advanced computer simulation techniques using ABAQUS/Explicit to investigate stress and strain at the surface and at the coating/substrate interface of multi-layer coatings under single particle impact. Eight different coating architectures and two material models were analyzed to determine possible stress reduction that could be obtained through a combination of layering patterns and material properties. Material models representing relevant coating and substrate properties were analyzed to assess their effect on modelling results. Specifically, the elastic and elastic-plastic coating models were used and the effect of increased plasticity on coating/substrate response was analyzed. In the current model, only the initial phase of the erosion process, i.e., conditions leading to crack nucleation were considered and the coating architecture was optimized using the lowest surface tensile stress criterion. It was found that stress reduction up to 3.6 times was possible for the optimized bi-layer coating. Overall, the most effective coating architectures were those combining low Young’s modulus in the top layer and high Young’s modulus in the bottom layer. |