Homogeneous plastic deformation in a Cu-based bulk amorphous alloy

The compressive deformation behavior of a cast Cu60Zr20Hf10Ti10 bulk metallic glass in the supercooled liquid region was investigated at strain rates ranging from 1×10−3 to 10−2 s−1. Glass transition and crystallization temperatures were determined by differential scanning calorimetry to be 721 and 766 K, respectively. Both strain rate and temperature were found to significantly affect deformation behavior in the supercooled liquid region. A strain rate change method was employed to obtain the strain rate sensitivity (m) and the maximum value of m was determined to be 0.61 at 750 K. A large compressive strain of 0.78 was achieved at a strain rate of 3×10−3 s−1 at 740 K. Structures of the amorphous material, both before and after deformation, were studied using X-ray diffraction and high-resolution transmission electron microscopy. The compressive properties are presented and discussed in light of the structural change.