Atomic-Scale Mechanism of Crack-Tip Plasticity: Dislocation Nucleation and Crack-Tip Shielding
- 18 August 1997
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review Letters
- Vol. 79 (7) , 1309-1312
- https://doi.org/10.1103/physrevlett.79.1309
Abstract
By isolating the process of dislocation emission from a crack tip under an applied tensile stress, we extract from a molecular dynamics simulation the atomic-level displacement and stress fields on the activated slip plane before and after the nucleation event. The stress-displacement relations so obtained provide a direct link with recent continuum descriptions of brittle versus ductile behavior in crack propagation. Crack-tip shielding by the emitted dislocations is demonstrated, as is the role of surface steps in dislocation nucleation and crack-tip blunting.Keywords
This publication has 18 references indexed in Scilit:
- Critical configurations for dislocation nucleation from crack tipsPhilosophical Magazine A, 1997
- Nucleation of dislocations from crack tips under mixed modes of loading: Implications for brittle against ductile behaviour of crystalsPhilosophical Magazine A, 1995
- Dislocation loops at crack tips: nucleation and growth— an experimental study in siliconMaterials Science and Engineering: A, 1993
- Dislocation nucleation from a crack tip: An analysis based on the Peierls conceptJournal of the Mechanics and Physics of Solids, 1992
- Dislocation nucleation at metal-ceramic interfacesActa Metallurgica et Materialia, 1992
- Dislocation emission from crack tipsPhilosophical Magazine A, 1991
- Direct observation of dislocation emission from crack tips in silicon at high temperaturesActa Metallurgica, 1989
- Molecular dynamics simulation of crack tip processes in alpha-iron and copperJournal of Applied Physics, 1983
- Ductile versus brittle behaviour of crystalsPhilosophical Magazine, 1974
- VI. The phenomena of rupture and flow in solidsPhilosophical Transactions of the Royal Society A, 1921