Oxidation Behavior and Oxide Transformation of a Pt-Modified Aluminide Coating at Moderate High Temperature

The oxidation performance of a single-phase Pt-modified aluminide coating was assessed in test at 980 °C comparison with the single crystal superalloy. results suggested that exhibited superior resistance. During oxidation, oxide scale formed on bare alloy changed constantly followed by constitution multi-layer structure: An outer mainly consisted Cr2O3 + NiCr2O4 TiO2 scarce protection, and an internal Al2O3. thickness increased time, where became looser more porous. Meanwhile, discontinuous. Oxygen nitrogen inwardly diffused into substrate, forming Ta2O5 TiN particles. In contrast to complex scale, uniform continuous Al2O3 aluminide-coated samples after for 1500 h, which showed no spallation cracking. Interestingly, θ-Al2O3 α-Al2O3 phases remained such long time. It is relatively lower temperature presence Pt retarded θ-α transformation. degradation rate from β-NiAl γ′-Ni3Al very slow coating. various development substrate individually studied.