Impact of thermal exposure of EB-PVD TBCs on young's modulus and sintering

摘要

Electron-beam physical vapor deposited (EB-PVD) thermal barrier coatings (TBCs) of partially yttria stabilized zirconia (PYSZ) on turbine airfoils are a promising approach to improve the overall economy of fuel dependent energy conversion systems. Essential properties are impaired in service. Sintering is mostly contributing to an increase in the Young's modulus and thermal conductivity. Future generation turbine blades require improved sinter resistant, stress tolerant, low thermal conductivity TBCs to battle these obstacles. This paper presents the sintering behavior of EB-PVD TBCs on substrates and in-plane Young's modulus measurements versus temperature. Sintering is followed by BET gas adsorption. In-plane Young's moduli of TBC/substrate composites are determined by dynamic-mechanical analysis (DMA). The results are discussed with regard to substrate effects, influence of TBC microstructure and composition. The feasibility of alternative TBC compositions will be addressed.