Comparison of Oxidation Behavior of Shot-Peened Plasma Spray Coatings with Cold Gas Dynamic Spray Coatings

Atmospheric plasma spray (APS) process is commonly used in the production of TBCs due to low cost, and rapid and easy production. Cold gas dynamic spray (CGDS) method is an emerging coating technology which provides the desired properties such as low porosity, low oxide content, and dense structure for production of ideal metallic bond coat layer compared to APS and the other thermal spray processes. Within the context of this study, shot-peening process was applied to bond coats produced by APS technique in order to improve its microstructural properties like CGDS bond coats. TBCs having APS, CGDS, and shot-peened APS bond coats were isothermally exposed to 1100 A degrees C for 8, 24, 50, and 100 h. Before and after oxidation tests, TBCs were examined and compared in terms of their microstructures and thermally grown oxide layer which forms at the interface of bond and top coats.