Influence of Water Vapor and Temperature on the Oxide Scale Growth and Alpha-Case Formation in Ti-6Al-4V Alloy

Abstract The Ti-6Al-4V alloy is extensively used in aerospace, automotive and biomaterial applications. In the aerospace industry, service temperature of currently limited to 350 °C due its insufficient oxidation resistance. Oxidation at higher temperatures causes formation a fast-growing oxide scale an oxygen-enriched subsurface layer, which known as “alpha-case.” Additionally, effect water vapor on behavior critical. present study, dry air containing 10 vol.% H 2 O 500, 600 700 for up 500 h has been investigated. main focus this study examination different morphologies along with oxygen enrichment zone. It observed that spallation more severe vapor-containing environment. air, morphology shows typical layered TiO /Al 3 structure after exposure 300 h, while Al precipitates are outermost part when oxidized wet air. This indicates solubility diffusivity 3+ ions influenced by vapor. addition, extent zone (alpha-case) function time determined nanoindentation profiles. was shown contrast formation, alpha-case thickness not affected presence atmosphere.