Study of medium range reordering by plastic deformation in Cu46Zr46Al8

The influence of shear in the atomic structure of ternary Cu46Zr46Al8 metallic glass was studied at different temperatures by molecular dynamics (MD) simulation. At temperatures above and below the glass transition temperature the system was subjected to a shear deformation cycle; the shear deformation was carried in the [100] direction and then the original geometry was recovered. The system was analyzed in three states: initial state (before deformation), deformed state (sheared) and final state (recovery). The different states obtained by the atomistic simulations were examined by computing the directional pair distribution functions (dPDF) in the coordinate planes. The results showed by dPDFs of the planes perpendicular to the coordinate axis are apparently isotropic. However, the dPDF disengage when computed perpendicular to rotated axis. This reveals that the anisotropy introduced during the deformation cycles appears in directions [110] and [11¯0], tilted 45° with respect to the direction of the applied shear. To analyze the subtle structural change we systematically computed the positions and widths of the dPDF peaks on the rotated directions, thence allowing us to describe in detail the different signatures of anisotropy induced by deformation in the metallic glasses.