Creep deformation in near-{gamma} TiAl. 2: Influence of carbon on creep deformation in Ti-48Al-1V-0.3C
- Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering
- Ford Motor Co., Dearborn, MI (United States). Materials Science Dept.
The influence of interstitial strengthening and microstructure on creep deformation has been examined in the near-{gamma} TiAl alloy Ti-48Al-1V-0.3C. Creep studies were conducted under constant load in air at 815 c in the stress range of 50 to 200 MPa. Significant improvement in creep resistance was observed in this alloy compared with a similar alloy (Ti-49Al-1V) containing low levels of carbon (0.07 at. pct). The degree of strengthening resulting from the addition of carbon was found to be dependent on microstructure. At 815 C and 150 MPa, the addition of carbon reduced the minimum creep rate by a factor of approximately 20 in the equiaxed {gamma} and duplex microstructures and by a factor of 3 in the fully lamellar microstructures. Carbide precipitation occurred in this alloy when aged in the temperature range of 700 C to 950 C. The addition of carbon leads to a decease in the stress exponent from 4 to 3 in the duplex and equiaxed {gamma} microstructures and the inhibition of sub-boundary formation in the duplex microstructure. This suggests that solute/dislocation interaction mechanisms, rather than a direct effect of carbide precipitates, are responsible for the significant increase in creep resistance observed in this alloy.
- OSTI ID:
- 131480
- Journal Information:
- Metallurgical Transactions, A, Journal Name: Metallurgical Transactions, A Journal Issue: 11 Vol. 26; ISSN 0360-2133; ISSN MTTABN
- Country of Publication:
- United States
- Language:
- English
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