Atomistic process of plastic deformation in a model amorphous metal

Abstract Elementary process of plastic deformation in a computer simulated metallic amorphous model which was subjected to shear deformation has been investigated by analysing spatial distributions of atomic displacement, atomic strain, atomic stresses, atomic shear modulus and atomic coordination expressed by Voronoi polyhedra. Plastic shear deformation took place at localized sites in a spherical shape with a diameter of 3–4 atomic distances. The deformation sites are characterized by an atomic pressure distribution around thc site which is arranged so as to assist the local deformation, and at the same time by a local mechanical instability expressed by a low atomic shear modulus which in turn is related to the Voronoi polyhedra type. It was also observed that adjacent deformation sites were transformed sequentially in the manner of a chain reaction, resulting in macroscopic slip.