Atomistic simulations of dislocation mobility in Al, Ni and Al/Mg alloys

Dislocation velocities and mobilities are studied using molecular dynamics simulations for edge and screw dislocations in pure aluminium and nickel, and edge dislocations in Al-2.5%Mg and Al-5.0%Mg random substitutional alloys using EAM potentials. In the pure materials, the velocities of all dislocations are close to linear with the ratio of (applied stress)/(temperature) at low velocities consistent with phonon drag models, and quantitative...