Deformation and fracture behavior of a directionally solidified {beta}/{gamma}{prime} Ni-30 at. pct. Al alloy
- Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering
- NASA Lewis Research Center, Cleveland, OH (United States)
The effect of a ductile {gamma}{prime}-Ni{sub 3}Al phase on the room-temperature ductility, temperature-dependent yield strength, and creep resistance of {beta}-NiAl was investigated. Room-temperature tensile ductility of up to 9 pct was observed in directionally solidified {beta}/{gamma}{prime} Ni-30 at. pct Al alloys, whereas the ductility of directionally solidified (DS), single-phase [001] {beta}-NiAl was negligible. The enhancement in ductility was attributed to a combination of slip transfer from the ductile {gamma}{prime} to the brittle {beta} phase and extrinsic toughening mechanisms such as crack blunting, deflection, and bridging. As in single-phase Ni{sub 3}Al, the temperature-dependent yield strength of these two-phase alloys increased with temperature with a peak of approximately 850 K. The creep strength of the {beta}/{gamma}{prime} alloys in the temperature range 1000 to 1200 K was found to be comparable to that of monolithic {beta}-NiAl. A creep strengthening phase needs to be incorporated in the {beta}/{gamma}{prime} microstructure to enhance the elevated temperature mechanical properties.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 347483
- Journal Information:
- Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 4 Vol. 30; ISSN 1073-5623; ISSN MMTAEB
- Country of Publication:
- United States
- Language:
- English
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