INVESTIGATIONS ON THE FORMATION OF INITIAL CRACKS IN THERMAL BARRIER COATINGS PREPARED BY EB-PVD
INVESTIGATIONS　ON　THE　FORMATION　OF　INITIAL　CRACKS　IN　THERMAL　BARRIER　COATINGS　PREPARED　BY　EB－PVD

This paper deals with the mechanism of the formation of initial cracks in the yttria partially stabilized zirconia thermal barrier coatings prepared by EB-PVD method.The microcracks were only recognized inside the ceramic top coat of the thermalcycled TBCs. SEM/EDS observations indicated 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.