Coupled Thermal and Mechanical Analysis of Thermal Barrier Coatings Under Gradient Exposure

The dynamic role of sintering in the lifetime of multilayer, multimaterial thermal barrier coatings (TBCs) has been probed through coupled kinetic, thermal, and mechanical models. Experimentally measured physical properties and analytical methods are integrated to understand the results of various novel laboratory-scale performance tests simulating realistic operating environments. Both isothermal and gradient tests are explored in this framework for single-layer yttria-stabilized zirconia (YSZ) and multilayer gadolinium zirconate-yttria-stabilized zirconia coatings. In both multilayer cases, failure between the two material layers can strongly be attributed to sintering, while failure between bond-coat TBC layers exhibits more ambiguity. Overall, this integrated computational materials engineering (ICME)-inspired framework demonstrates utility in understanding the failure of novel multilayer coating architectures. Further use in manufacturing is envisioned by incorporating the effects of process variation through the coating's starting properties and microstructure.

Automated summary

The dynamic role of sintering in the lifetime of multilayer thermal barrier coatings has been explored, with failure mainly attributed to sintering between the layers in multilayer cases. The ambiguity of failure between bond-coat TBC layers is also noted. The integrated computational materials engineering framework shows utility in understanding novel multilayer coating architectures and could be further applied in manufacturing.