Influence of twist angle on crack propagation of nanoscale bicrystal nickel film based on molecular dynamics simulation

YQ Zhang and SY Jiang and XM Zhu and YN Zhao, PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES, 87, 281-294 (2017).

DOI: 10.1016/j.physe.2016.11.005

Tensile deformation of nanoscale bicrystal nickel film with twist grain boundary, which includes various twist angles, is investigated via molecular dynamics simulation to obtain the influence of twist angle on crack propagation. The twist angle has a significant influence on crack propagation. At the tensile strain of 0.667, as for the twist angles of 0 degrees, 3.54 degrees and 7.05 degrees, the bicrystal nickel films are subjected to complete fracture, while as for the twist angles of 16.1 degrees and 33.96 degrees, no complete fracture occurs in the bicrystal nickel films. When the twist angles are 16.1 degrees and 33.96 degrees, the dislocations emitted from the crack tip are almost unable to go across the grain boundary and enter into the other grain along the slip planes 111. There should appear a critical twist angle above which the crack propagation is suppressed at the grain boundary. The higher energy in the grain boundary with larger twist angle contributes to facilitating the movement of the glissile dislocation along the grain boundary rather than across the grain boundary, which leads to the propagation of the crack along the grain boundary.

Return to Publications page