Effect of Deposition Parameters on the Microstructure and Growth Rate of CVD Mullite Environmental Barrier Coatings

摘要

Si-based ceramics such as SiC require environmental barrier coatings to protect against hot-corrosion and recession in gas turbine applications. Dense, crystalline mullite coatings of uniform thickness have been deposited by hot-wall chemical vapor deposition (CVD) on SiC substrates, using the AlCl_3-SiCl_4-CO_2-H_2 system. The effects of the CVD deposition parameters such as temperature, total reactor pressure, and metal-chloride partial pressure on the coating microstructure and growth kinetics have been investigated, and are discussed in this paper.