A Stochastically Generated Geometrical Finite Element Model for Predicting the Residual Stresses of Thermally Sprayed Coatings Under Different Process Parameters

In this work, a 3D stochastic model coupled with a finite element (FE) code is used to investigate the development of residual stresses in thermally sprayed coatings. The residual stresses of a thermally sprayed yttria-stabilized zirconia (YSZ) coating applied to stainless steel substrates are used for this work. The formation of the coating layers was simulated with a 3D stochastic model, SimCoat. Three YSZ coating models with a similar average thickness, but different layers (one-, two-, and three-layer coatings) were obtained by changing three process parameters: the material feed rate, the gun velocity, and the total number of passes. Two 2D slices of each 3D model were taken and converted into FE models using an in-house Python code. An FE simulation was then used to study the combined effect of these process parameters on the development of residual stresses. The variation of in-plane stresses through the thickness for each model was obtained, and a comparison between the developed stresses was conducted. The developed methodology was effective for understanding the effect of the coating process parameters on the development of residual stresses and can be used to optimize the coating process parameters to obtain the desired residual stresses.