A real time deformation evaluation method for surface and interface of thermal barrier coatings during 1100 °C thermal shock

A simple high temperature resistant speckle manufacturing technology and a high temperature micro digital image correlation method were developed and applied to study the real time deformation of thermal barrier coatings' (TBCs) near-interface regions and surfaces during a thermal shock of 1100 degrees C. This method was used to measure the displacement and strain fields of TBCs and to analyze the strain evolution of TBCs at high temperature. During the thermal shock heating stage, tensile and shear strain concentrations were found in the ceramic coat near the ceramic coat/bond-coat interface, indicating that the inner regions of the ceramic coat near the interface are a weak link because of the tensile and shear stress concentrations here during the process of thermal shock cycles. Experimental results show that this method can be applied to strain distribution regularity investigation of TBCs' near-interface regions and surfaces in an 1100 degrees C thermal shock environment.