Oxidation resistance of NiAl based alloys depends on the formation of slow growing protective Al_2O_3 scales. Several types of Al_2O_3 scale have been found to form on alumina-forming alloys, such as meta-stable γ-Al_2O_3, δ-Al_2O_3, θ-Al_2O_3, and stable α-Al_2O_3. α-Al_2O_3 is a good protective oxide scale because of its thermodynamic stability and slow growth rate. At lower temperatures and/or in the early stages of oxidation, the meta-stable oxides γ-Al_2O_3, δ-Al_2O_3 and θ-Al_2O_3 grow. Since the formation of the protective α-Al_2O_3 scale is delayed on high Al-content β-NiAl alloy, promotion of rapid growth of α-Al_2O_3 is strongly required. In this study, Ni layer containing Fe_2O_3 powder in nano-scale was electrodeposited on Ni 50% Al alloy as a seed layer for promotion of α-Al_2O_3 growth. Incorporation of Fe_2O_3 crystal in a seed layer is expected to enhance the formation of α-Al_2O_3 at high temperature due to its isomorphism with α-Al_2O_3.
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