Atomistic simulation of effects of surface notches and loading mode on deformation and mechanics of ZrNi metallic glass

The effects of surface notches and loading mode on the mechanical deformation and mechanics of ZrNi metallic glass (MG) are studied using molecular dynamics simulations based on the many-body embedded-atom potential. The effects are investigated in terms of atomic trajectories, shear strain distributions, and stress-strain curves. The simulation results show that for ZrNi MG, resistance to shear deformation (shear strain > 200%) before breaking is much greater than that to tensile and compressive deformation. For ZrNi MG under tension, a pre-existing notch leads to earlier necking and breaking. Significant stress concentration occurs around the notch root when the notch length (L) is 3 nm or above, and dominates plastic deformation. For ZrNi MG under compression, a pre-existing notch is completely filled by neighboring atoms at the initial stage of compression. A pre-existing notch leads to single-edge barreling and weakens a sample’s ultimate strength when the L value is 3 nm or above. For ZrNi MG under shear loading, a pre-existing notch does not influence the shear modulus of samples; however, their ultimate strength decreases with increasing L value.