Advanced gas turbine engine designs continue to push into regimes of higher operating temperatures and increased pressures. Materials capable of functioning under these extreme conditions have been sought by both government and industry. As part of its mission, the NASA Transformational Tools and Technologies (TTT) Project, under the auspices of NASA’s Aeronautics Research Mission Directorate (ARMD), has been pursuing high temperature materials development with the performance goal of 2700°F (1482°C) operation. This goal has evolved into a focused three year Technology Challenge which is nearing its conclusion. This challenge problem has sought to develop high temperature materials for turbine engines which will enable a 6% reduction in fuel burn for commercial aircraft as compared to the current generation. This ambitious effort has included ceramic matrix composite (CMC) compositions, architectures and processing as well as environmental barrier coating compositions (EBC) and processing routes. It has included collaborators and materials suppliers from both industry and academia. The development and validation of thermomechanical models and computational tools for design, analysis, and life prediction have been an important part of this effort. Evaluation of CMC/EBCs included various aspects of thermomechanical testing from coupon testing for strength and creep resistance, to materials evaluation under conditions similar to aspects of engine operation. Simulated engine testing of airfoil subcomponents in a P&W test rig is the final evaluation step following years of materials development. As this three year Technical Challenge concludes, plans are under development for continued environmental durability investigation of CMC/EBC systems accompanied by validated durability modeling.
High-Temperature Fatigue Behaviour of Austenitic Stainless Steel : Influence of Ageing on Thermomechanical Fatigue and Creep-Fatigue Interaction
