Article ID Journal Published Year Pages File Type
5440084 Corrosion Science 2017 9 Pages PDF
Abstract
Oxidation mechanisms in polycrystalline Co-Ni-Cr-Al-W-Ta alloys were investigated using O16/O18 isotopic tracer analysis in the focused ion-beam secondary ion mass spectrometer (FIB-SIMS). It was found that Al additions favour the formation of a continuous alumina-rich layer, that Cr indirectly improved oxidation resistance and that increasing the Co fraction resulted in poorer oxidation performance. In the alloy containing 15 at.% Cr and 10 at.% Al, the outer scale formed after 200 h oxidation at 800 °C comprised oxides less than 1 μm thick. It is concluded that protective oxide scales can be formed in Co-Ni base superalloys.
Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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