Evaluation of shear delamination strength of thermal barrier coating after heating by torsion pin-test method

•Torsion pin-test method was established for estimating adhesive strength of coatings.•Identical shear adhesive strength of thermal barrier coatings could be obtained.•The strength of the stress singularity dominates the adhesive strength of the coating.•The interfacial adhesive strength of TBCs increased after heating.

In this study, the torsion pin-test method that as originally presented by the author was applied to investigate the shearing delamination strength of thermal barrier coatings. By comparing the corresponding FEM analysis to the obtained experimental results, finally, the delamination criteria for the thermal barrier coating before and after heating were found to be expressed using the stress intensity factor and the stress gradient of the shear singular stress distributions around the interface edge between the top-coat and the bond coat.