Accelerated molecular dynamics simulations of dislocation climb in nickel

Molecular-dynamics Simulations of Nickel Clusters

Structural stability and energetics of nickel clusters, NiN (N = 3−459), have been investigated by molecular-dynamics simulations. A size-dependent empirical model potential energy function has been used in the simulations. Stable structures of the microclusters with sizes N = 3 − 55 and clusters generated from fcc crystal structure with sizes N = 79 − 459 have been determined by molecular-dyna...

Dislocation patterning: The role of climb in meso-scale simulations

Simulation of parallel dynamics of edge dislocations in a 2D hexagonal lattice is carried out on a large scale by means of coarse graining, in the absence of external strain. In order to study the effect of climb on dislocation pattern formation, we allowed (i) isotropic (ii) biased (iii) only glide mobility. Moreover we annihilated dislocations with opposite Burgers vectors close to each other...

Dislocation climb models from atomistic scheme to dislocation dynamics

We develop a mesoscopic dislocation dynamics model for vacancy-assisted dislocation climb by upscalings from a stochastic model on the atomistic scale. Our models incorporate microscopic mechanisms of (i) bulk diffusion of vacancies, (ii) vacancy exchange dynamics between bulk and dislocation core, (iii) vacancy pipe diffusion along the dislocation core, and (iv) vacancy attachment-detachment k...

Dislocation dynamics in nanocrystalline nickel.

It is believed that the dynamics of dislocation processes during the deformation of nanocrystalline materials can only be visualized by computational simulations. Here we demonstrate that observations of dislocation processes during the deformation of nanocrystalline Ni with grain sizes as small as 10 nm can be achieved by using a combination of in situ tensile straining and high-resolution tra...

Predicting dislocation climb: Classical modeling versus atomistic simulations