The Effect of Crystallographic Orientation on Void Growth: A Molecular Dynamics Study

In ductile materials, fracture involves void nucleation, growth and coalescence. The objective of this research is to understand how crystallographic orientation influences void growth in uniaxial tensile deformation of aluminum. We used molecular dynamics to simulate void growth in a spherical void embedded cubic specimen with periodic boundary conditions under remote uniaxial tension. The simulation results reveal how crystallographic orientation affects the yield stress and void growth corresponding to dislocation nucleation from the void surface and resulting in shear loops in perfect FCC lattice. Varying dislocation patterns/shear loops occur according to the specimens different orientations, thereby affirming the effect of crystallographic orientation. Consequently, atomistic simulations of this type can indeed inform continuum void growth models for application in multiscale models.