Details
| Original language | English |
|---|---|
| Pages (from-to) | 429-433 |
| Number of pages | 5 |
| Journal | Materials Science and Engineering A |
| Volume | 510-511 |
| Issue number | C |
| Publication status | Published - 15 Jun 2009 |
| Externally published | Yes |
Abstract
This study reports on the creep-fatigue interaction of the oxide dispersion strengthened Ni-base superalloy PM 1000. Fully reversed symmetrical push-pull isothermal fatigue, thermomechanical fatigue (TMF), slow-fast and tensile hold time tests were conducted in the temperature range from 450 to 1050 °C. TMF tests resulted in unexpectedly low fatigue lives. Grain boundary cavitation observed in the in-phase TMF tests indicated that creep damage plays an important role under TMF loading conditions. Similarly, fatigue life dependence on wave-shape demonstrated that creep-fatigue tests exhibit the shortest cyclic life due to the additional creep damage in the tensile-going part of the cycle. Damage mechanisms were observed to vary substantially depending on the test mode. In the creep-fatigue tests, the grain boundaries of fine equiaxed grains triggered multiple internal crack initiation, thereby pointing to the adverse effects of these microstructural features. Cavitation occurs by a local stress directed diffusion and growth of voids, as evidenced by dispersoid free zones in areas near the transverse grain boundary cavities. Time-dependent damage occurring at and above 850 °C in the creep-fatigue tests is mostly due to creep whereas environmental attack plays only a minor role.
Keywords
- Creep-fatigue interaction, Cyclic deformation behaviour, Damage mechanisms, Fatigue life, Nickel-base ODS superalloy, Thermomechanical 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
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In: Materials Science and Engineering A, Vol. 510-511, No. C, 15.06.2009, p. 429-433.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Creep-fatigue interaction of the ODS superalloy PM 1000
AU - Ngala, W. O.
AU - Maier, H. J.
PY - 2009/6/15
Y1 - 2009/6/15
N2 - This study reports on the creep-fatigue interaction of the oxide dispersion strengthened Ni-base superalloy PM 1000. Fully reversed symmetrical push-pull isothermal fatigue, thermomechanical fatigue (TMF), slow-fast and tensile hold time tests were conducted in the temperature range from 450 to 1050 °C. TMF tests resulted in unexpectedly low fatigue lives. Grain boundary cavitation observed in the in-phase TMF tests indicated that creep damage plays an important role under TMF loading conditions. Similarly, fatigue life dependence on wave-shape demonstrated that creep-fatigue tests exhibit the shortest cyclic life due to the additional creep damage in the tensile-going part of the cycle. Damage mechanisms were observed to vary substantially depending on the test mode. In the creep-fatigue tests, the grain boundaries of fine equiaxed grains triggered multiple internal crack initiation, thereby pointing to the adverse effects of these microstructural features. Cavitation occurs by a local stress directed diffusion and growth of voids, as evidenced by dispersoid free zones in areas near the transverse grain boundary cavities. Time-dependent damage occurring at and above 850 °C in the creep-fatigue tests is mostly due to creep whereas environmental attack plays only a minor role.
AB - This study reports on the creep-fatigue interaction of the oxide dispersion strengthened Ni-base superalloy PM 1000. Fully reversed symmetrical push-pull isothermal fatigue, thermomechanical fatigue (TMF), slow-fast and tensile hold time tests were conducted in the temperature range from 450 to 1050 °C. TMF tests resulted in unexpectedly low fatigue lives. Grain boundary cavitation observed in the in-phase TMF tests indicated that creep damage plays an important role under TMF loading conditions. Similarly, fatigue life dependence on wave-shape demonstrated that creep-fatigue tests exhibit the shortest cyclic life due to the additional creep damage in the tensile-going part of the cycle. Damage mechanisms were observed to vary substantially depending on the test mode. In the creep-fatigue tests, the grain boundaries of fine equiaxed grains triggered multiple internal crack initiation, thereby pointing to the adverse effects of these microstructural features. Cavitation occurs by a local stress directed diffusion and growth of voids, as evidenced by dispersoid free zones in areas near the transverse grain boundary cavities. Time-dependent damage occurring at and above 850 °C in the creep-fatigue tests is mostly due to creep whereas environmental attack plays only a minor role.
KW - Creep-fatigue interaction
KW - Cyclic deformation behaviour
KW - Damage mechanisms
KW - Fatigue life
KW - Nickel-base ODS superalloy
KW - Thermomechanical fatigue
UR - http://www.scopus.com/inward/record.url?scp=65049086194&partnerID=8YFLogxK
U2 - 10.1016/j.msea.2008.06.056
DO - 10.1016/j.msea.2008.06.056
M3 - Article
AN - SCOPUS:65049086194
VL - 510-511
SP - 429
EP - 433
JO - Materials Science and Engineering A
JF - Materials Science and Engineering A
SN - 0921-5093
IS - C
ER -