Effect of 0. 1 atomic percent zirconium on the cyclic oxidation behavior of beta-NiAl for 300 hours at 1200 C
The long time effect of 0.1 at percent Zr (0.2 wt percent Zr) on the cyclic oxidation behavior of hipped beta-NiAl was studied. Oxidation testing was performed in static air at 1200 C for up to 3000 one-hour exposure cycles. Specific weight change versus time data was modeled with the COSP computer program to analyze cyclic oxidation behavior. The Zr-free stoichiometric alloy oxidized and spalled randomly to bare metal between cycles at a rate high enough to deplete Al to a low enough level that oxidation breakaway took place as nonprotective NiO replaced the alpha-Al{sub 2}O{sub 3}/NiAl{sub 2}O{sub 4} scale as the controlling oxide. The Zr minimized this severe type of spalling maintaining the protective alpha-Al{sub 2}O{sub 3} scale even out to 3000 hours for the stoichiometric alloy with no significant Al depletion. A third beta-NiAl alloy containing 0.1 at percent Zr but with 10 percent less Al than the stoichiometric alloy was also tested and showed some depletion of Al, but the protective Al{sub 2}O{sub 3}/NiAl{sub 2}O{sub 4} was still maintained to close to 2700 hours.
- Research Organization:
- National Aeronautics and Space Administration, Cleveland, OH (USA). Lewis Research Center
- OSTI ID:
- 5788204
- Report Number(s):
- N-89-13566; NASA-TM-101408; E-4366; NAS-1.15:101408; CONF-8809190-
- Resource Relation:
- Conference: Workshop on the oxidation of high-temperature intermetallics, Cleveland, OH (United States), 22-23 Sep 1988
- Country of Publication:
- United States
- Language:
- English
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