Details
| Original language | English |
|---|---|
| Pages (from-to) | 328-341 |
| Number of pages | 14 |
| Journal | Acta materialia |
| Volume | 59 |
| Issue number | 1 |
| Publication status | Published - 20 Oct 2010 |
| Externally published | Yes |
Abstract
In many engineering applications, fatigue is the dominant failure mechanism governing the life of a component. Thus, many studies have focused on this phenomenon, although there is a need for a model that addresses fatigue based on the material's microstructure, specifically the energetics of the grain boundaries (GBs) and persistent slip bands (PSBs). Our approach is to model the energy of a PSB structure and use its stability with respect to dislocation motion as our failure criterion for fatigue crack initiation. The components that contribute to the energy of the PSB are identified, namely the stress field resulting from the applied external forces, dislocation pile-ups and work-hardening of the material is calculated at the continuum scale. Further, energies for dislocations creating slip in the matrix/precipitates, interacting with the GBs and nucleating/agglomerating within the PSB are computed via molecular dynamics. The results of our simulations on the stability of a PSB produce the correct fatigue crack initiation trends for the grain size, grain orientation, character of the GB, precipitate volume fraction and applied strain. From this information, we see that distinct GBs act as strong barriers to slip and increase the fatigue strength of the material.
Keywords
- Coincidence site lattice (CSL), Crack initiation, Fatigue, Grain boundaries, Persistent slip bands
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Materials Science(all)
- Ceramics and Composites
- Materials Science(all)
- Polymers and Plastics
- Materials Science(all)
- Metals and Alloys
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In: Acta materialia, Vol. 59, No. 1, 20.10.2010, p. 328-341.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - A physically based fatigue model for prediction of crack initiation from persistent slip bands in polycrystals
AU - Sangid, Michael D.
AU - Maier, Hans J.
AU - Sehitoglu, Huseyin
N1 - Funding information: Support for this work was provided by Rolls-Royce Corporation and the National Science Foundation, DMR 08-03270.
PY - 2010/10/20
Y1 - 2010/10/20
N2 - In many engineering applications, fatigue is the dominant failure mechanism governing the life of a component. Thus, many studies have focused on this phenomenon, although there is a need for a model that addresses fatigue based on the material's microstructure, specifically the energetics of the grain boundaries (GBs) and persistent slip bands (PSBs). Our approach is to model the energy of a PSB structure and use its stability with respect to dislocation motion as our failure criterion for fatigue crack initiation. The components that contribute to the energy of the PSB are identified, namely the stress field resulting from the applied external forces, dislocation pile-ups and work-hardening of the material is calculated at the continuum scale. Further, energies for dislocations creating slip in the matrix/precipitates, interacting with the GBs and nucleating/agglomerating within the PSB are computed via molecular dynamics. The results of our simulations on the stability of a PSB produce the correct fatigue crack initiation trends for the grain size, grain orientation, character of the GB, precipitate volume fraction and applied strain. From this information, we see that distinct GBs act as strong barriers to slip and increase the fatigue strength of the material.
AB - In many engineering applications, fatigue is the dominant failure mechanism governing the life of a component. Thus, many studies have focused on this phenomenon, although there is a need for a model that addresses fatigue based on the material's microstructure, specifically the energetics of the grain boundaries (GBs) and persistent slip bands (PSBs). Our approach is to model the energy of a PSB structure and use its stability with respect to dislocation motion as our failure criterion for fatigue crack initiation. The components that contribute to the energy of the PSB are identified, namely the stress field resulting from the applied external forces, dislocation pile-ups and work-hardening of the material is calculated at the continuum scale. Further, energies for dislocations creating slip in the matrix/precipitates, interacting with the GBs and nucleating/agglomerating within the PSB are computed via molecular dynamics. The results of our simulations on the stability of a PSB produce the correct fatigue crack initiation trends for the grain size, grain orientation, character of the GB, precipitate volume fraction and applied strain. From this information, we see that distinct GBs act as strong barriers to slip and increase the fatigue strength of the material.
KW - Coincidence site lattice (CSL)
KW - Crack initiation
KW - Fatigue
KW - Grain boundaries
KW - Persistent slip bands
UR - http://www.scopus.com/inward/record.url?scp=78049527162&partnerID=8YFLogxK
U2 - 10.1016/j.actamat.2010.09.036
DO - 10.1016/j.actamat.2010.09.036
M3 - Article
AN - SCOPUS:78049527162
VL - 59
SP - 328
EP - 341
JO - Acta materialia
JF - Acta materialia
SN - 1359-6454
IS - 1
ER -