An atomistic investigation into the nature of near threshold fatigue crack growth in aluminum alloys

Despite decades of study, the atomic-scale mechanisms of fatigue crack growth remain elusive. Here we use the coupled atomistic–discrete dislocation method, a multiscale simulation method, to examine the influence of dislocation glide resistance on near-threshold fatigue crack growth in an aluminum alloy. The simulations indicate that the threshold increases with an increase in dislocation glide resistance, and that a transition in the crack growth direction can occur when dislocation nucleation is inhibited by other nucleated dislocations. Three main mechanisms of fatigue crack propagation are observed: cleavage along the primary slip plane, crack extension by dislocation emission, and crack extension by opening along lattice defects.


Published in:
Engineering Fracture Mechanics, 115, 111-121
Year:
2014
Publisher:
Elsevier
ISSN:
0013-7944
Keywords:
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 Record created 2014-11-26, last modified 2018-03-17

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