Multi-dimensional simulations of the chemical vapor deposition for thermal barrier coatings using ZrCl4–H2–CO2–Ar gas mixtures

Two- and three-dimensional simulations of the chemical vapor deposition processes for zirconia thermal barrier coating have been made using FLUENT. Validation runs in a simple reactor geometry yield results that match the experimental data for a range of temperature and pressure conditions. The two-dimensional models involving realistic inflow and outflow, along with a turbine blade located within for deposition, show details of the flow, thermal and chemical processes that can be used to optimize the deposition characteristics. However, some of the flow and deposition characteristics are only captured in full three-dimensional simulations where flow recirculation effects are observed. Thus, simulations of the zirconia chemical vapor deposition can be made with reasonable accuracy even with a simplified one-step reaction mechanism.