AN INVESTIGATION INTO THE EFFECT OF CRITICAL PARAMETERS ON RESIDUAL STRESS BUILD-UP IN THERMAL BARRIER COATING

摘要

Thermal barrier coatings (TBCs) are widely used on different hot components of gas turbine engines such asblades and vanes. Although, several mechanisms for the failure of the TBCs have been suggested, it is largelyaccepted that the durability of these coatings is primarily determined by the residual stresses that are developedduring the thermal cycling. In the present study, the residual stress build-up in an electron beam physicalvapour deposition (EB-PVD) based TBC on a coupon during thermal cycling has been studied by varying threeparameters such as cooling rate, TBC thickness and substrate thickness. A two-dimensional thermo-mechanicalplane strain finite element simulations have been performed for thousand cycles. It was observed that thesevariations change the stress profile significantly and stress severity factor increases non-linearly. Overall, thepredictions of the model agree with reported experimental as well as simulated results.