Dislocations in interfaces in the h.c.p. metals. 1: Defects formed by absorption of crystal dislocations
- Univ. Politecnica de Catalunya, Barcelona (Spain). Dept. de Matematica Aplicada III
- Univ. of Liverpool (United Kingdom). Dept. of Engineering
Atomic-scale computer simulation techniques have been used to investigate the interaction of crystal dislocations with two interfaces in hexagonal-close-packed (h.c.p.) metals, namely the {l_brace}10{bar 1}2{r_brace} twin boundary and a <1{bar 2}10>/90{degree} tilt boundary which is incommensurate in the direction perpendicular to the tilt axis. Crystal dislocations are always found to be absorbed in the tilt boundary with concomitant reconstruction of their cores. In the twin boundary, a broader range of interactions is observed, including defect transmission from matrix to twin and decomposition in the interface into discrete defects. The easy generation of mobile twinning dislocations facilitates the latter behavior. The simulations demonstrate that the core structures of localized interfacial defects exhibit preferred riser configurations. For the twin, the favored structure is the basal-on-prism configuration, whereas risers in the tilt boundary resemble {l_brace}10{bar 1}2{r_brace} twin forms. By comparing interaction processes in two interfaces, this investigation elucidates the role of crystallographic considerations and interfacial structure. It also illustrates that the core structure of interfacial defects can be complex and contributes significantly to total defect energy.
- OSTI ID:
- 345096
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Journal Issue: 5 Vol. 47; ISSN 1359-6454; ISSN ACMAFD
- Country of Publication:
- United States
- Language:
- English
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