Advanced thermal protection coatings

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Thermal barrier coatings (TBCs) have been used in aircraft gas turbines for several decades. One of the early deposition methods for thermal barrier coatings , i.e. air plasma spray (APS), is still being used today for producing TBCs made of yttria-stabilized zirconia (YSZ). However these coatings have limitations in terms of long time exposure at high temperature. More importantly, new generations of gas turbine engines especially in aero-engines demand for TBCs with higher temperature resistance and performance. A higher temperature has direct effect on lower operating costs and carbon emission of the engines.This project is focused on advanced TBCs with improved performance for aero-engines. The project tackles three major steps in the development of novel TBCs. It approaches this challenge first through microstructural improvement toward an advanced engineered nanostructured coating made of gadolinium zirconate (GZO), a ceramic still more resistant to high temperature. In this approach, APS deposition is optimized within an ideal process window to generate an engineered microstructure that yields up to 50% reduction of the coating thermal conductivity compared to TBCs currently used in industry. The project will advance in parallel by detailed computational and experimental studies on an emerging spray process i.e., suspension plasma spray (SPS), which can provide nanostructured coatings with substantially lower thermal conductivity and improved mechanical performance. Finally the project will address the development of new materials/compositions for better performance at higher temperatures through computational methods based on the atomistic characteristics of the constituting elements.