Advanced Multi-layered Thermal Barrier Coatings - An Overview

A new type of thermal barrier coating must be developed to protect the underlying metallic components from higher operating temperatures in order to enhance the fuel efficiency of the gas turbine engine. Yttria stabilised zirconia (YSZ) is a conventionally used top coat material for a thermal barrier coating (TBC) system. However, YSZ cannot work above 1200°C due to its sintering effect. As a replacement of this coating various types of multilayer coatings have been developed by researchers. These coatings should fulfil both mechanical and thermal requirements of the TBCs. The current paper focuses on providing an overview regarding advanced multilayer thermal barrier coatings suitable for the future generation gas turbine applications.