Numerical Analysis of Residual Stress in a Gradient Surface Coating

There were conducted numerical analyses of thermal residual stress in a double gradient surface coating consisting of porous ZrO2 of 500 m thickness, placed on Inconel 718 substrate, with an interlayer of NiCoCrAlY of 200 m thickness. It was assumed that the coating was deposited by plasma spraying. It showed out roughness of the free surface and borders between material phases. Numerical model took into consideration the real geometry of material structure. The results were analysed after transforming them into discrete distributions of particular components of stress. Distributions were presented for particular zones of the surface coating. This allowed to obtain signals originated by distinct features of the material structure such as particular material phases, their contact borders, pores, roughness of the external surface, roughness of internal borders between layers of the gradient system and others.