Computational Materials Science
Instrumented indentation has been suggested as a method to determine interfacial fracture toughness of thermal barrier coatings. However, in a previous experimental study we showed that the results are ambiguous. In this work, we investigate the experimental results by numerical simulations incorporating the material microstructure. In the numerical simulations, based on finite element analyses, the stress fields that are associated with the loading and unloading of the indenter are investigated. By comparing these stress fields to the damage observed in the experimental study, including crack path and interfacial delaminations, we explain key findings from the experimental observations. Our results suggest that indentation testing of multilayered coated structures might not induce the delamination in the overall weakest interface and therefore the test results must be evaluated with care.
Yan, J., Karlsson, A. M., Bartsch, M., 2009, "On Stresses Induced in a Thermal Barrier Coating due to Indentation Testing," Computational Materials Science, 44(4) pp. 1178-1191.
NOTICE: this is the author’s version of a work that was accepted for publication in Computational Materials Science. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Computational Materials Science, 44, 4, (02-01-2009); 10.1016/j.commatsci.2008.07.037