High-Temperature Coatings for Turbine Blades and Vanes

This Small Business Technology Transfer Program (STTR) Phase I project seeks to develop a new oxidation barrier for preventing oxidation of the bond-coat in current state-of-the art thermal barrier coatings (TBCs). TBCs have been applied to the hot sections of aircraft turbine engines to increase engine efficiency and to extend the life of metal components; however, they have not been fully integrated to the engine design due to the potential catastrophic failures at the interfaces where crack formation takes place. This failure is closely linked to the thermally grown oxide (TGO) layer on the bond-coats during thermal exposures. Due to this fact, current efforts are focused on developing new alloys or barrier coatings, but only minimal benefits have been achieved. We propose the development of a new oxidation barrier layer based on yttrium aluminates that react to form YAG (Y3Al5O12) to solve the oxidation problems of the bond coats. During Phase I, we will also try to deposit a single phase rare earth orthophosphate (LaPO4) in order to seek a new TBC system exhibiting a high thermal insulation efficiency as well as a high thermochemical stability.