Modeling and Simulation of Microstructure Formation for Porosity Prediction in Thermal Barrier Coatings Under Air Plasma Spraying Condition

Effective physical and mechanical properties of thermal barrier coatings are strongly dependent on the coating microstructure. The main objective of this study is the coating porosity prediction during the coating formation by simulation. For this purpose, two simulation approaches are presented. The first model takes into account physical impact, deformation, and overlying of powder particles on the solid substrate. Therefore, computational fluid dynamics and the volume of fluid method for this model were used. In the second approach, a faster and therefore more efficient model was developed, hence it was strongly simplified to simulate the formation of coatings and their microstructure. The splat formation was handled by calculating the flattening degree as a function of the Reynolds number. The disc-shaped particles were discretized by cuboids. The neighboring cuboids are moveable against each other at their contact areas. The displacement of those depends on material properties and the Reynolds number as well. Both approaches for predicting the microstructure were mutually compared.