NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Diffusional transport and predicting oxidative failure during cyclic oxidation of beta-NiAl alloysNickel aluminides (NiAl) containing 40-50 at. percent Al and up to 0.1 at. percent Zr have been studied following cyclic oxidation at 1200, 1300, 1350 and 1400 C. The selective oxidation of aluminum resulted in the formation of protective Al2O3 scales on each alloy composition at each temperature. However, repeated cycling eventually resulted in the gradual formation of less protective NiAl2O4. The appearance of the NiAl2O4, signaling the end of the protective scale-forming capability of the alloy, was related to the presence of gamma-prime-(Ni3Al) which formed as a result of the loss of aluminum from the sample. A simple methodology is presented to predict the protective life of beta-NiAl alloys. This method predicts the oxidative lifetime due to aluminum depletion when the aluminum concentration decreases to a critical concentration. The time interval preceding NiAl2O4 formation (i.e., the lifetime based on protective Al2O3 formation) and predicted lifetimes are compared and discussed. Use of the method to predict the maximum use temperature for NiAl-Zr alloys is also discussed.
Document ID
19930066373
Document Type
Reprint (Version printed in journal)
Authors
Nesbitt, J. A.
(NASA Lewis Research Center Cleveland, OH, United States)
Vinarcik, E. J.
(NASA Lewis Research Center Cleveland, OH, United States)
Barrett, C. A.
(NASA Lewis Research Center Cleveland, OH, United States)
Doychak, J.
(NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1992
Publication Information
Publication: Materials Science and Engineering, Part A -Structural Materials: Properties, Microstructure, Microstructure and Processing
ISSN: 0921-5093
Subject Category
Metallic Materials
Distribution Limits
Public
Copyright
Other
No Preview Available