Abstract
The purpose of this study was to understand the effect of spraying method on residual stress in thermally grown oxide (TGO) on NiCrA1Y coating. NiCrAlY alloy coat was sprayed by Air plasma spraying (APS) and high velocity oxygen-fuel spraying (HVOF), respectively, on a nickel based superalloy. The microstructure of NiCrAIY coating layer was observed by using scanning electron microscope (SEM). The element distribution of NiCrAlY coating layer was investigated by using electron probe micro analyzer (EPMA). The residual stress in TGO was measured by photo luminescence piezo-spectroscopy (PLPS), which increased with an increase in thermal exposure time. The residual stress of APS coating at 1000°C was higher than that of HVOF coating. However, residual stress of the APS coating at 1100°C was almost the same as that of HVOF coating.
