Details
| Original language | English |
|---|---|
| Pages (from-to) | 625-630 |
| Number of pages | 6 |
| Journal | Materials Science and Engineering A |
| Volume | 319-321 |
| Publication status | Published - Dec 2001 |
| Externally published | Yes |
Abstract
Fatigue tests were performed on smooth cylindrical specimens of a near-y titanium aluminide alloy with a duplex microstructure. The test temperature ranged from 500 to 750 °C in the isothermal tests and these temperatures were also used as minimum and maximum temperature of in-phase and out-of-phase thermo-mechanical fatigue (TMF) tests. Environmental degradation was studied running the experiments in air and high-vacuum, respectively, and the microstructural changes were characterized by transmission electron microscopy. Fatigue behavior was found to be strongly affected by temperature as a consequence of a change in the cyclic stress-strain response at ≈ 650 °C. At temperatures < 650 °C, initial cyclic hardening occured, whereas > 650 °C a cyclic saturation state was observed from the beginning. With increasing temperature, fatigue life decreased in vacuum, but increased in air indicating an abnormal (inverse) environmental effect. The stress-strain behavior under TMF conditions resembles that of the corresponding isothermal experiments. Out-of-phase thermo-mechanical fatigue was found to be more detrimental than in-phase, because of the positive (tensile) mean stress arising in out-of-phase testing in combination with the pronounced mean stress sensitivity of the relatively brittle alloy.
Keywords
- Environmental effect, High-temperature fatigue, Near-γ titanium aluminide, Thermo-mechanical fatigue
ASJC Scopus subject areas
- Materials Science(all)
- General Materials Science
- Physics and Astronomy(all)
- Condensed Matter Physics
- Engineering(all)
- Mechanics of Materials
- Engineering(all)
- Mechanical Engineering
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Materials Science and Engineering A, Vol. 319-321, 12.2001, p. 625-630.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - High-temperature fatigue behavior of a near-γ titanium aluminide alloy under isothermal and thermo-mechanical conditions
AU - Christ, H. J.
AU - Fischer, F. O.R.
AU - Maier, H. J.
PY - 2001/12
Y1 - 2001/12
N2 - Fatigue tests were performed on smooth cylindrical specimens of a near-y titanium aluminide alloy with a duplex microstructure. The test temperature ranged from 500 to 750 °C in the isothermal tests and these temperatures were also used as minimum and maximum temperature of in-phase and out-of-phase thermo-mechanical fatigue (TMF) tests. Environmental degradation was studied running the experiments in air and high-vacuum, respectively, and the microstructural changes were characterized by transmission electron microscopy. Fatigue behavior was found to be strongly affected by temperature as a consequence of a change in the cyclic stress-strain response at ≈ 650 °C. At temperatures < 650 °C, initial cyclic hardening occured, whereas > 650 °C a cyclic saturation state was observed from the beginning. With increasing temperature, fatigue life decreased in vacuum, but increased in air indicating an abnormal (inverse) environmental effect. The stress-strain behavior under TMF conditions resembles that of the corresponding isothermal experiments. Out-of-phase thermo-mechanical fatigue was found to be more detrimental than in-phase, because of the positive (tensile) mean stress arising in out-of-phase testing in combination with the pronounced mean stress sensitivity of the relatively brittle alloy.
AB - Fatigue tests were performed on smooth cylindrical specimens of a near-y titanium aluminide alloy with a duplex microstructure. The test temperature ranged from 500 to 750 °C in the isothermal tests and these temperatures were also used as minimum and maximum temperature of in-phase and out-of-phase thermo-mechanical fatigue (TMF) tests. Environmental degradation was studied running the experiments in air and high-vacuum, respectively, and the microstructural changes were characterized by transmission electron microscopy. Fatigue behavior was found to be strongly affected by temperature as a consequence of a change in the cyclic stress-strain response at ≈ 650 °C. At temperatures < 650 °C, initial cyclic hardening occured, whereas > 650 °C a cyclic saturation state was observed from the beginning. With increasing temperature, fatigue life decreased in vacuum, but increased in air indicating an abnormal (inverse) environmental effect. The stress-strain behavior under TMF conditions resembles that of the corresponding isothermal experiments. Out-of-phase thermo-mechanical fatigue was found to be more detrimental than in-phase, because of the positive (tensile) mean stress arising in out-of-phase testing in combination with the pronounced mean stress sensitivity of the relatively brittle alloy.
KW - Environmental effect
KW - High-temperature fatigue
KW - Near-γ titanium aluminide
KW - Thermo-mechanical fatigue
UR - http://www.scopus.com/inward/record.url?scp=0035699284&partnerID=8YFLogxK
U2 - 10.1016/S0921-5093(00)02013-X
DO - 10.1016/S0921-5093(00)02013-X
M3 - Article
AN - SCOPUS:0035699284
VL - 319-321
SP - 625
EP - 630
JO - Materials Science and Engineering A
JF - Materials Science and Engineering A
SN - 0921-5093
ER -