Modeling the Deposition Process of Thermal Barrier Coatings

Thermal barrier coatings produced by plasma spraying have a characteristic microstructure of lamellae, pores, and cracks. The lamellae form when particles splash onto the substrate. As the coating grows, the lamellae pile on top of one another, producing an interlocking structure. In most cases the growth is rapid and chaotic, resulting in a microstructure characterized by pores and cracks. This paper presents an improved model for the deposition process of thermal barrier coatings. The task of modeling the coating growth is divided into two parts. First, a description of the particle on arrival at the film is given based on the available theoretical, numerical, and experimental findings. Second, a set of physically based rules for combining these events to obtain the film is defined and discussed. The splats run along the surface and are permitted to curl up (producing pores) or to interlock. The computer model uses a mesh to combine these processes and build the coating. The proposed...