Finite Sized Atomistic Simulations of Screw Dislocations

Abstract

The interaction of screw dislocations with an applied stress is studied using atomistic simulations in conjunction with a continuum treatment of the role played by the far field boundary condition. A finite cell of atoms is used to consider the response of dislocations to an applied stress and this introduces an additional force on the dislocation due to the presence of the boundary. Continuum mechanics is used to calculate the boundary force which is subsequently accounted for in the equilibrium condition for the dislocation. Using this formulation, the lattice resistance curve and the associated Peierls stress are calculated for screw dislocations in several close packed metals. As a concrete example of the boundary force method, we compute the bow out of a pinned screw dislocation; the line-tension of the dislocation is calculated from the results of the atomistic simulations using a variational principle that explicitly accounts for the boundary force.

LaTex, 20 pages, 11 figures

References in corpus (1)

• Interatomic potentials from first-principles calculations: the force-matching method

Cited by in corpus (6)

• Atomistic simulations of dislocation mobility in Al, Ni and Al/Mg alloys
• First principles determination of the Peierls stress of the shuffle screw dislocation in silicon
• Ab initio and finite-temperature molecular dynamics studies of lattice resistance in tantalum
• Lattice Resistance and Peierls Stress in Finite-size Atomistic Dislocation Simulations
• Accurate Calculations of the Peierls Stress in Small Periodic Cells
• Efficient flexible boundary conditions for long dislocations