Evolution of Thermal Barrier Coatings for Land Based Gas Turbines at MHI

Abstract

This paper describes the development and verification of a thermal barrier coating (TBC) for use in class 1600 °C turbines. It explains how ceramic materials with different crystal structures were selected for the topcoat and how they were screened based on phase transformations. It discusses the method used determine a bond coat composition with high oxidation resistance and good ductility. It describes the TBC deposition process, the tuning of spray parameters, and the optimization of coating properties. It discusses the tests used to evaluate the topcoat, bond coat, and thermally grown oxide (TGO) layer and presents the results of 10,000 h of field testing in a power plant.