On the Mechanical Response in a Thermal Barrier System Due to Martensitic Phase Transformation in the Bond Coat
Journal of Engineering Materials and Technology - Transactions of the ASME
Recentstudies have shown that Pt-aluminide—a common bond coat material inthermal barrier coatings—undergoes martensitic transformations during thermal cycling. The transformationsare associated with both large transformation strain and a strainhysteresis, leading to accumulation of a mismatch strain. Thermal barriersystems based on Pt-aluminide bond coats are susceptible to interfacialmorphological instabilities. In this study, we investigate how the cyclicmartensitic transformation influences the morphology. Two key results are: (i)the morphological instabilities are highly sensitive to the thermo-mechanical propertiesof the substrate due to the martensitic transformation; (ii) thehysteresis associated with cyclic martensitic transformation cannot drive the morphologicalinstabilities; the strains associated with the formation of the thermallygrown oxide do
Karlsson, A. M., 2003, "On the Mechanical Response in a Thermal Barrier System due to Martensitic Phase Transformation in the Bond Coat," Journal of Engineering Materials and Technology, 125(4) pp. 346-352.