Details
| Original language | English |
|---|---|
| Pages (from-to) | 2531-2547 |
| Number of pages | 17 |
| Journal | Acta materialia |
| Volume | 61 |
| Issue number | 7 |
| Publication status | Published - 15 Feb 2013 |
Abstract
The description of fatigue crack growth in metals has remained an empirical field. To address the physical processes contributing to crack advance a model for fatigue crack growth (FCG) has been developed utilizing a combined atomistic-continuum approach. In particular, the model addresses the important topic of the role of nanoscale coherent twin boundaries (CTB) on FCG. We make the central observation that FCG is governed by the dislocation glide resistance and the irreversibility of crack tip displacement, both influenced by the presence of CTBs. The energy barriers for dislocation slip under cyclical conditions are calculated as the glide dislocation approaches a twin boundary and reacts with the CTB. The atomistically calculated energy barriers provide input to a mechanics model for dislocations gliding in a forward and reverse manner. This approach allows the irreversibility of displacement at the crack tip, defined as the difference between forward and reverse flow, to be determined. The simulation results demonstrate that for both refinement of twin thickness and a decrease in crack tip to twin spacing FCG resistance improves, in agreement with recent experimental findings reported in the literature.
Keywords
- Coherent twin, Damage tolerance, Fatigue, Nanocrystalline, Nickel
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. 61, No. 7, 15.02.2013, p. 2531-2547.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Modeling fatigue crack growth resistance of nanocrystalline alloys
AU - Chowdhury, Piyas B.
AU - Sehitoglu, Huseyin
AU - Rateick, Richard G.
AU - Maier, Hans J.
N1 - Funding information: Support for this work was provided primarily by Honeywell Aerospace Corporation. We acknowledge the use of the parallel computing resource, the Taub cluster, at the University of Illinois.
PY - 2013/2/15
Y1 - 2013/2/15
N2 - The description of fatigue crack growth in metals has remained an empirical field. To address the physical processes contributing to crack advance a model for fatigue crack growth (FCG) has been developed utilizing a combined atomistic-continuum approach. In particular, the model addresses the important topic of the role of nanoscale coherent twin boundaries (CTB) on FCG. We make the central observation that FCG is governed by the dislocation glide resistance and the irreversibility of crack tip displacement, both influenced by the presence of CTBs. The energy barriers for dislocation slip under cyclical conditions are calculated as the glide dislocation approaches a twin boundary and reacts with the CTB. The atomistically calculated energy barriers provide input to a mechanics model for dislocations gliding in a forward and reverse manner. This approach allows the irreversibility of displacement at the crack tip, defined as the difference between forward and reverse flow, to be determined. The simulation results demonstrate that for both refinement of twin thickness and a decrease in crack tip to twin spacing FCG resistance improves, in agreement with recent experimental findings reported in the literature.
AB - The description of fatigue crack growth in metals has remained an empirical field. To address the physical processes contributing to crack advance a model for fatigue crack growth (FCG) has been developed utilizing a combined atomistic-continuum approach. In particular, the model addresses the important topic of the role of nanoscale coherent twin boundaries (CTB) on FCG. We make the central observation that FCG is governed by the dislocation glide resistance and the irreversibility of crack tip displacement, both influenced by the presence of CTBs. The energy barriers for dislocation slip under cyclical conditions are calculated as the glide dislocation approaches a twin boundary and reacts with the CTB. The atomistically calculated energy barriers provide input to a mechanics model for dislocations gliding in a forward and reverse manner. This approach allows the irreversibility of displacement at the crack tip, defined as the difference between forward and reverse flow, to be determined. The simulation results demonstrate that for both refinement of twin thickness and a decrease in crack tip to twin spacing FCG resistance improves, in agreement with recent experimental findings reported in the literature.
KW - Coherent twin
KW - Damage tolerance
KW - Fatigue
KW - Nanocrystalline
KW - Nickel
UR - http://www.scopus.com/inward/record.url?scp=84875211672&partnerID=8YFLogxK
U2 - 10.1016/j.actamat.2013.01.030
DO - 10.1016/j.actamat.2013.01.030
M3 - Article
AN - SCOPUS:84875211672
VL - 61
SP - 2531
EP - 2547
JO - Acta materialia
JF - Acta materialia
SN - 1359-6454
IS - 7
ER -