Development of Nanostructured Thermal Barrier Coatings

In this paper, nanostructured 5-8wt.% yttria stabilized zirconia (5-8YSZ) thermal barrier coating (TBC) deposited by air plasma spraying (APS) of powder and new TBC with novel structure deposited by solution precursor plasma spray (SPPS) are compared. Plasma spray conditions, coating forming mechanisms, microstructures, phase compositions, thermal conductivities, and thermal cycling lives of the APS nanostructured TBC and the SPPS nanostructured TBC are discussed. The SPPS process is different from either physical/chemical vapor deposition process or conventional plasma spray deposition in the aspects of substrate temperature, coating forming mechanism, growth rate, and coating structure.