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

Room-temperature mechanical properties of Cu 50 Zr 40 Ti 10– x Ni x (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 Cu 50 Zr 40 Ti 10 BMG when the loading rate is 1×10 −4 s −1 , while for Cu 50 Zr 40 Ti 10– x Ni x ( x =1–3, mole fraction, %) BMGs when the loading rate is 1×10 −2 s −1 . The plastic strain ( ɛ p ), yielding strength ( σ y ) and fracture strength ( σ f ) of the studied Cu-based BMGs significantly depend on the aspect ratio and the loading rate. In addition, the σ y of the studied Cu-based BMGs with an aspect ratio of 1:1 is close to the σ f 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.