High-temperature degradation of advanced gas turbine engine materials and coatings

High temperature oxidation is one of the predominant mechanism of material and coating degradation in gas turbine engines. Components in the hot end of the compressors undergo some oxidation under mechanical fretting wear or fatigue conditions. Turbine components such as nozzle guide vanes and blades with complex cooling configurations undergo severe oxidation and generally protected by high temperature coatings. Performance of these component materials such as titanium alloy, mechanically alloyed and directionally solidified superalloy materials with or without a protective coating is discussed from an oxidation point of view. Influence of the thermo-mechanical fatigue cracking on the turbine blade oxidation behaviour is presented.