Computer simulation of screw dislocation interactions with twin boundaries in h.c.p. metals
- Univ. Politecnica de Catalunya, Barcelona (Spain). Dept. de Matematica Aplicada 3
- Univ. of Liverpool (United Kingdom). Dept. of Materials Science and Engineering
The interaction of matrix screw dislocations with twin boundaries has been simulated by computer for different h.c.p. models representing {alpha}-titanium and magnesium. The atomic structure of the screw core in these two models is appropriate for crystals that slip predominantly on the prism and basal planes, respectively, and this behavior is summarized in the first part of the paper. Then the movement under three different components of applied strain of the 1/3 <11{bar 2}0> matrix screw dislocation (in both its prism and basal forms) into the boundary of the {l_brace}10{bar 1}2{r_brace} and {l_brace}10{bar 1}1{r_brace} twins is described for the geometry where the screw is parallel to the interface. The screw crosses the {l_brace}10{bar 1}2{r_brace} boundary by cross-slip, onto either of the two slip systems, but the {l_brace}10{bar 1}1{r_brace} boundary usually absorbs the screw by a process of decomposition into two twinning dislocations. This behavior and the glide resistance are discussed in terms of the interfacial structure of the twins and the properties of twinning dislocations.
- OSTI ID:
- 178011
- Journal Information:
- Acta Metallurgica et Materialia, Journal Name: Acta Metallurgica et Materialia Journal Issue: 12 Vol. 43; ISSN 0956-7151; ISSN AMATEB
- Country of Publication:
- United States
- Language:
- English
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