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, 2 × 10⁻³, and 2 × 10⁻⁴·s⁻¹ 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 × 10⁻²·s⁻¹. However, the medial state occurs at the strain rates of 2 × 10⁻³·s⁻¹, and eventually the self-organized critical (SOC) behavior appears at the strain rate of 2 × 10⁻⁴·s⁻¹. 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 × 10⁻⁴·s⁻¹. The values of the goodness of fit are 0.95 and 0.99 at the strain rates of 2 × 10⁻³ and 2 × 10⁻⁴·s⁻¹, 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.

The strain-rate-dependent plasticity under uniaxial compression at the strain rates of 2 × 10⁻³, 2 × 10⁻⁴ and 2 × 10⁻⁵ s⁻¹ in a Pd_77.5Cu₆Si_16.5 alloy is investigated. At different strain rates, the serration events exhibit different amplitudes and time scales. The intersection effects take place obviously, and the loading time is much longer than the relaxation time in the serration event at three strain rates. However, the time intervals between two neighboring serrations lack any time scale, and the elastic energy density displays a power-law distribution at the strain rate of 2 × 10⁻³ s⁻¹, which means that the self-organized critical (SOC) behavior emerges with increasing strain rates.