Effects of aspect ratio and loading rate on room-temperature mechanical properties of Cu-based bulk metallic glasses

Abstract

Room-temperature mechanical properties of Cu50Zr40Ti10–xNix (0≤x≤4, mole fraction, %) bulk metallic glasses (BMG) with aspect ratios in the range of 1:1–2.5:1 and loading rates in the range of 1×10−5–1×10−2 s−1 were systematically investigated by room-temperature uniaxial compression test. In the condition of an aspect ratio of 1:1, the superplasticity can be clearly observed for Cu50Zr40Ti10 BMG when the loading rate is 1×10−4 s−1, while for Cu50Zr40Ti10–xNix (x=1–3, mole fraction, %) BMGs when the loading rate is 1×10−2 s−1. The plastic strain (ɛp), yielding strength (σy) and fracture strength (σf) of the studied Cu-based BMGs significantly depend on the aspect ratio and the loading rate. In addition, the σy of the studied Cu-based BMGs with an aspect ratio of 1:1 is close to the σf of those with the other aspect ratios when the loading rate is 1×10−2 s−1. The mechanism for the mechanical response to the loading rate and the aspect ratio was also discussed.