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Title: Influences of superalloy composition and Pt content on the oxidation behavior of gamma–gamma prime NiPtAl bond coatings

Here, the effects of superalloy composition and Pt content on the high-temperature oxidation behavior of γ–γ’ NiPtAl diffusion coatings were investigated over the temperature range of 1050–1150 °C. Simple NiPtAl diffusion coatings with 7 or 12 µm electroplated Pt thickness were evaluated in 1-h cycles in dry O2 for up to 2500 cycles on four superalloys: directionally solidified (DS) alloy 142, 1st generation single-crystal (SX) alloy 1483, and 2nd generation SX alloys X4 and N5. Coatings on high-Hf alloy 142 experienced severe internal oxidation of Hf at all temperatures. Coatings on ~5 at.% Ti alloy 1483 were protective at 1050 °C, but exhibited severe scale spallation at 1100 °C, with extensive formation of Ti- and Ni-rich oxides at the gas interface. Coatings with 7-µm Pt on X4 were extremely protective at 1100 °C, but failed rapidly at 1150 °C, which also was associated with the formation of Ti-rich oxides. Increasing the coating Pt content on X4 improved the 1150 °C oxidation behavior. Coatings on Ti-free N5 showed the best performance at 1150 °C, especially with 12-µm Pt. Although γ–γ’ coatings can exhibit outstanding cyclic oxidation resistance with minimal Al depletion, they appear to be sensitive to substrate composition, as wellmore » as eventual Pt depletion due to interdiffusion.« less
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  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Oxidation of Metals
Additional Journal Information:
Journal Name: Oxidation of Metals; Journal ID: ISSN 0030-770X
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). High Temperature Materials Laboratory (HTML)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Country of Publication:
United States
36 MATERIALS SCIENCE oxide scale; aluminide; coating; platinum; TBC; diffusion coating; high-temperature oxidation; bond coating; gamma prime