Oxidation resistance of C/C composites coated with SiC and glass materials under conditions of gas fuel combustion

C/C composites are one of the promising candidates for heat-resistant materials because they have a high strength and good creep resistance at high temperatures. Their application as a material for gas turbine blades would increase the thermal efficiency of gas turbine systems. In this study, the effects of SiC coating on oxidation resistance of C/C composites in the combustion field have been investigated. CVD (Chemical Vapor Deposition) and pack cementation are employed as coating methods. The time changes in weight loss of the specimens coated by the CVD method proved to be minimal, the coating layer was easily peeled off from the substrate. On the other hand, the layer of the specimens coated by the pack cementation method has been found to be stable. However, the substrate was degraded because of oxygen penetration through the pores in the coating layer. In order to cover the pores, the specimens were additionally coated with glass materials. No weight loss occurred for the double-coated specimens. This coating technique seems to be promising for improving the oxidation resistance of C/C composites in the combustion field.