Solute-dislocation interaction in Mg from first-principles: and twinning dislocations with flexible boundary conditions
- University of Illinois at Urbana-Champaign
We relax the cores of $$\langle c+a \rangle$$ edge and screw dislocations, and $$(10\overline{1}2)$$ and $$(10\overline{1}1)$$ twinning dislocations in Mg using first-principles calculations with flexible boundary conditions (FBC). FBC couple highly distorted cores to a harmonic lattice through lattice Green functions (LGF), allowing dislocations to relax as isolated defects. Unlike previous FBC calculations using bulk LGFs, we use LGFs specifically for dislocated geometries. The optimized geometries provide sites for computing solute-dislocation interactions via direct substitution, as well as local strain and slip for input to computationally efficient geometric solute interaction models. The interactions are inputs for solid-solution strengthening models. We compute interactions between Al, Ca, Mn, Sn, and Zn and the dislocations, and predict corresponding changes in stress for dislocation motion. We compare the strengthening of each of these non-basal deformation modes to basal strengthening and examine implications for ductility in Mg alloys. Funding from DOE-USAMP Cooperative Agreement Number DE-EE0007756.
- Research Organization:
- Univ. of Illinois at Urbana-Champaign, IL (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE)
- DOE Contract Number:
- EE0007756
- OSTI ID:
- 1501683
- Resource Relation:
- Conference: TMS Annual Meeting & Exhibition; San Antonio, Texas; March 10-14, 2019
- Country of Publication:
- United States
- Language:
- English
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