Low-temperature anomaly of plasticity of Zr_64,13Cu _15,75Ni_10,12Al₁₀ bulk metallic glass

Compression plastic deformation and failure of cylindrical samples of Zr_64.13Cu_15.75Ni_10.12Al₁₀ bulk metallic glass were studied in the temperature range of 300-4.2 K. At temperature T = 300 K the deformation curve is serrated due to the propagation of narrow shear bands. At a deformation level of about 3-4% a catastrophic, uncontrolled failure of the specimens occurs resulting from the propagation of the macroscopic shear band at a rate ∼ 10³ m/s comparable with the sound velocity. A decrease of temperature from 300 K down to 170 and 77 K changes the type of deformation curves from the jump-like type to a smooth one. An interesting low-temperature anomaly of the deformation process has been registered: at temperatures of 170 and 77 K a «slow» propagation of the single macroscopic shear band at a rate of about 10^-6 m/s is observed. Cooling down to 4.2 K causes the macroscopic plasticity of the specimens to disappear, and their failure results (as in the case of 300 K) from the propagation of the catastrophic shear band at a nearsonic velocity.