Molecular Dynamics Simulations. Molecular Dynamics Simulation of Ni Crystals under Uniaxial Deformation.

Molecular dynamics simulation of Ni crystal under uniaxial elongation and compressive deformation was performed for NPH and NVE ensembles using Finnis-Sinclair and Morse potentials from the view point of deformation induced phase transformation. In the case of NPH ensemble using Morse and Finnis-Sinclair potentials, the structure breaks down immediately above the elastic limit of elongation. The fcc structure changes into the hcp structure with the deformation of simulation-cell under compressive stress. In the case of NVE ensemble using Morse and Finnis-Sinclair potentials under tensile deformation, slip deformation occurs in the plastic region, and the strain does not recover even though the stress is removed. Under the compressive stress, the structure is deformed by slip and becomes the twin like crystal structure elastically.