<p> The role of plastic deformation in the initiation and propagation of cracks in Cu-17Al alloy embrittled by liquid mercury has been studied. It is proposed that extensive plastic deformation and work hardening must occur at the crack-tip during propagation in order to raise the local flow stress to a critical level at which the maximum normal stress is equal to the cohesive strength. A crack initiation mechanism is proposed involving grain boundary diffusion enhanced by the stress concentration at the head of dislocation pile-ups at the grain boundary. Micro-cracks are formed at the weakened grain boundary and a period of stable crack growth made over a period of increasing applied stress may be necessary before the crack is long enough to become unstable.</p> / Thesis / Master of Science (MSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/17930 |
| Date | 07 1900 |
| Creators | Hancock, Peter Colin |
| Contributors | Ives, M.B., Embury, J.D., None |
| Source Sets | McMaster University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
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