The Self-Organized Critical Behavior in Pd-based Bulk Metallic Glass

Bulk metallic glasses (BMGs) deform irreversibly through shear banding manifested as serrated-flow behavior during compressive tests. The strain-rate-dependent plasticity under uniaxial compression at the strain rates of 2 × 10, 2 × 10, and 2 × 10·s in a Pd-based BMG is investigated. The serrated flow behavior is not observed in the stress-strain curve at the strain rate of 2 × 10·s. However, the medial state occurs at the strain rates of 2 × 10·s, and eventually the self-organized critical (SOC) behavior appears at the strain rate of 2 × 10·s. The distribution of the elastic energy density shows a power-law distribution with the power-law exponent of −2.76, suggesting that the SOC behavior appears. In addition, the cumulative probability is well approximated by a power-law distribution function with the power-law exponent of 0.22 at the strain rate of 2 × 10·s. The values of the goodness of fit are 0.95 and 0.99 at the strain rates of 2 × 10 and 2 × 10·s, respectively. The transition of the dynamic serrated flows of BMGs is from non-serrated flow to an intermediate state and finally to the SOC state with decreasing the strain rates. OPEN ACCESS