The mechanism of power-law scaling behavior by controlling shear bands in bulk metallic glass

Bulk metallic glasses deform irreversibly under a stress through shear-banding courses that manifest as the serrated flow behavior. The compressive deformation and dynamic serrated flow behavior of Zr_52.5Cu_17.9Ni_14.6Al₁₀Ti₅ bulk metallic glass samples with different aspect ratios have been investigated. The yield strength nearly remains a constant value of approximately 2GPa, while the compressive plasticity increases obviously with decreasing aspect ratio. It is found that the serrated flows display a power-law scaling behavior at different aspect ratios. The power-law scaling behavior is discussed by controlling shear bands in BMG. In addition, a new method was proposed to study the power-law-scaling behavior. When the aspect ratio is small, the friction between the sample and the platen will play a significant role that attributes to a lateral constraint. The uniaxial stress and the lateral constraint will cause a hydrostatic pressure on the sample close to the platen. The shear bands are controlled by the different stress states, which leads to a power-law-scaling behavior in serrated flows. The investigations have a contribution to understanding the plastic-deformation mechanism of BMGs.