Abstract
The effects and mechanisms of low cycle fatigue (LCF) on subsequent high cycle fatigue (HCF) limit were investigated in nickel-base superalloy Udimet 720 at room temperature at a stress ratio of 0.1 and frequencies of 1 and 25 Hz for LCF and HCF, respectively. The HCF limits were determined after various fractions of LCF life consumption. Results show that small fractions of LCF life consumption significantly reduce the subsequent HCF limit, and the reduction is attributed to a combination of LCF damage and the plastic deformation induced during the LCF process. Microstructural characterization indicates that both LCF and plastic deformation reduce the HCF limit by activating the slip systems in the FCC structure of the material, creating favorable sites for easy subsequent HCF damage.
| Original language | English |
|---|---|
| Pages (from-to) | 236-248 |
| Number of pages | 13 |
| Journal | Materials Science and Engineering: A |
| Volume | 332 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - Jul 2002 |
| Externally published | Yes |
Funding
The authors would like to express their appreciation to the US Air Force for the financial support of this program, and to Mr K.E. Goecke, Mr D. Maxwell and Mr Dale Osborne of University of Dayton Research Institute, Mr R. Lewis and Ms L. Piazza of UES for technical support whenever needed. Thanks also go to Dr Tim Gabb of NASA Glenn, Drs Paul Browning and Eric Ott of Caterpillar Co. for supply of experimental materials and technical discussion. W. Ren is supported under the RMAT-5 program administered by SFC.
| Funders | Funder number |
|---|---|
| Mr Dale Osborne of University of Dayton Research Institute | |
| U.S. Air Force |
Keywords
- High cycle fatigue
- Life prediction
- Low cycle fatigue
- Ni-base superalloy
- Plastic deformation