On the deformation mechanisms in metallic glasses

The deformation of metallic glasses (MG) may be considered on the basis of three models: the STZ (shear transformation zone) model; the free-volume model; and dislocation plastic flow. For the example of MG on the iron base, it is shown that dislocation plastic flow occurs at low temperatures; the activation energy is a few tens of eV. At higher temperatures, plastic deformation occurs with an activation energy of a few eV, which is close to the activation energy of self-diffusion. That corresponds to the first two models.