Scaling behavior and complexity of plastic deformation for a bulk metallic glass at cryogenic temperatures.

We explore the scaling behavior and complexity in the shear-branching process during the compressive deformation of a bulk metallic glass Zr(64.13)Cu(15.75)Al(10)Ni(10.12) (at. %) at cryogenic temperatures. The fractal dimension of the stress rate signal ranges from 1.22 to 1.72 with decreasing temperature and a larger shear-branching rate occurs at lower temperature. A stochastic model is introduced for the shear-branching process. In particular, at a temperature of 213K, the shear-branching process evolves as a self-similar random process. In addition, the complexity of the stress rate signal conforms to the larger activation energy of the shear transformation zone at lower temperatures.