Modelling the microstructure of thermal barrier coatings

Thermal barrier coatings produced by plasma spraying have a characteristics microstructure of lamellae, pores and cracks. The lamellae are produced by the splashing of particles onto the substrate. As the coating grows, the lamellae pile on top of each other, producing an interlocking structure. In most cases the growth is rapid an chaotic. The result is a microsturcture characterised by pores and cracks. We present an improved model for the deposition process of thermal barrier coatings. The task of modelling the coating growth is split into two parts: first we consider a description of the particle on arrival at the film, based on the available theoretical, numerical and experimental findings. Second we define and discuss a set of physically-based rules for combining these events to obtain the film. The splats run along the surface and are permitted to curl up (producing pores) or interlock. The computer model uses a mesh to combine these processes and build the coating. We discuss t...