Al2O3-modified PS-PVD 7YSZ thermal barrier coatings for advanced gas-turbine engines

Plasma spray-physical vapor deposition (PS-PVD), called the third-generation method for thermal barrier coatings (TBCs) fabrication, has great potential for their using in gas-turbine engines. Compared to atmospheric plasma spray (APS), called the first-generation TBCs, and electron beam-PVD (EB-PVD), called the second generation, PS-PVD has many interesting features, including non-line sight deposition, high deposition rate, and microstructural flexibility, among others. Such advantages make them a promising approach to prepare thermal barrier coatings for advanced gas-turbine engines. Using PS-PVD, feather-like columnar TBCs with good strain tolerance and low thermal conductivity can be fabricated. However, prior to their application in gas-turbine engines, some disadvantages, such as CMAS (CaO–MgO–Al2O3–SiO2, etc.) corrosion and oxidation resistance, need to be addressed. In this work, a method to develop Al2O3-modified PS-PVD 7YSZ TBCs was proposed. The experimental results demonstrate that the Al2O3-modification process is an effective approach to address the aforementioned weaknesses of traditional PS-PVD 7YSZ TBCs.