Environmental Durability of Mullite Coating/SiC and Mullite-YSZ Coating/SiC Systems

Abstract

An environmental protection scheme is necessary to realize the full potential of SiC as a high temperature structural material. Mullite and mullite-yttria stabilized zirconia (YSZ) dual layer coatings have been developed to provide environmental protection for SiC. Preliminary tests show that mullite coatings are promising for protection against molten salt corrosion and mullite-YSZ coatings are promising for protection in oxidizing/reducing gases and water vapor.