Thermal Barrier Coatings on Nickel Superalloy Substrates

Thermal barrier coatings (TBCs), which comprise metallic and ceramic multilayers, have been widely used in the hot section of aeroturbine engines to increase turbine efficiency and to extend the life of metallic components. An improvement in TBCs requires a better understanding of the complex changes in their structure and properties that occur under harsh operating conditions that eventually lead to their failure. In this paper, the developments of TBCs over the past 30 years are briefly reviewed. A description of materials issues involved in the state-of-art and next generation TBCs systems is presented, together with a summary of the current understanding of failure mechanisms; highlighting the challenges and prospects in TBCs research.