Investigations on the formation of initial cracks in thermal barrier coatings prepared by EB-PVD

The mechanism of the formation of initial cracks in the yttria partially stabilized zirconia thermal barrier coatings prepared by EB-PVD method was dealt with. The microcracks are only recognized inside the ceramic top coat of the thermal-cycled TBCs (thermal barrier coatings). SEM/EDS observations indicate that some special oxides exist in the area just below the cracks. It seems that the formation of the initial cracks can result from the oxidation stress as well as the thermal stress.