Investigation of interfacial properties of atmospheric plasma sprayed thermal barrier coatings with four-point bending and computed tomography technique

► Interfacial toughness of APS TBCs was examined with a modified four-point bending. ► Delamination mainly occurred in the TBC just above the TBC/bond coat interface. ► Calculated energy release rate increased from ~ 50 to ~ 120 J/m− 2 after heat treatment. ► Tomography was used to observe microstructural evolution non-destructively. ► 3D interface was reconstructed and interfacial roughness was obtained.