A batch preparation of large-size graphite plate/SiC coating by CVD: CFD simulation and experimental

Graphite substrate, as one of metal-organic chemical vapor deposition (MOCVD) equipment, often fails due to corrosion and powder loss during service. SiC is an ideal protective coating on graphite substrate surfaces due to its excellent properties. Currently, the preparation of SiC coating on large-size graphite substrates by chemical vapor deposition (CVD) in batches is extensively concerned. The coating was affected by various deposition processes during deposition due to the complexity of CVD. The deposition process of CVD needed to be optimized for batch preparation of large-size graphite plate/SiC coating. However, the temperature field and airflow field distribution inside the CVD equipment and the variation of SiC deposition mass fraction were challenging to obtain by instrumental measurement in the experiments. Herein, the optimization of the CVD process was guided by using Computational Fluid Dynamics (CFD) simulation. Five deposition processes, such as graphite plate placement, diameter, deposition temperature, reaction gas flow, and graphite plate rotational speed, were selected for the investigation. The simulation results were validated by CVD experiments. Optimal process parameters for the batch preparation of large-size graphite plate/SiC coating by CVD were obtained. Guidance for future batch production of coating on a large-size substrate by CVD was provided.