抄録
To improve the thermal efficiency of a gas turbine, thermal barrier coatings (TBC) have been developed to protect superalloy components. The damage in TBC is often caused by mechanical and thermal residual stress in TBC. Therefore, it is very important to evaluate residual stress distribution in TBC coating system. In this study, the residual stress of TBC has been measured by Raman spectroscopy. The testing material is a plasma-sprayed TBC containing 8% Y_2O_3 on a stainless steel. To understand the residual stress near interface, the TBC dissolved from the substrate has also been used to measure residual stress. The sharp raman peak exists at a frequency of 640 (cm)^<-1> for the tetragonal zirconia. It has been found that compressive stress in TBC system can be released in the TBC without substrate. However, this occurs with a thickness up to 100 μm.
