Abstract
In this study, laser shock peening (LSP) was used to treat NiCoCrAlY coating prepared via arc ion plating (AIP), which is to improve the high temperature oxidation resistance of NiCoCrAlY coating. The oxidation condition is continuous oxidation at 1100 ℃. The results showed that after 150 h oxidation, the samples without LSP treatment had oxide film damage and large-area internal oxidation, and the coating nearly failed. The samples treated by LSP had intact oxide film and strong antioxidant properties. This is attributed to the fact that LSP helps to eliminate large particle clusters on the sample surface, which provides a prerequisite for the uniform growth of thermally grown oxide (TGO). Furthermore, LSP introduces high density dislocations, high density stacking faults and twins, which refines the grains of the coating and provides more diffusion channels for the selective oxidation of Al elements. Due to above reasons, LSP treated sample can form a continuous and uniform Al2O3 oxide scale faster at the initial stage of oxidation, which hinders the diffusion reaction of other elements and keeps TGO in a stable growth stage for a long time. It is proved that LSP is a potential technology for improving the oxidation resistance of NiCoCrAlY coating.
Published Version
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