Deformation behaviors of a Ti-based bulk metallic glass composite in the dendrite softening region

Deformation behaviors of the Ti50Zr20Nb12Cu5Be13 bulk metallic glass composite in the dendrite softening region have been investigated using uniaxial compressive and tensile tests. All the compressive stress-strain curves show work-hardening phenomenon with the same tendency, the tensile stress-strain curves show work-softening phenomenon. The strain rate sensitivity exponent ranges from 0.061 to 0.072 in the compressive tests, and 0.33 to 0.38 in the tensile tests. The activation volume of the Ti50Zr20Nb12Cu5Be13 bulk metallic glass composite at 710 K ranges from 1.6 nm3 to 2.5 nm3 under compressive tests and 1.0 nm3 to 2.7 nm3 under tensile tests, indicating that there is a migration of atomic group (about 170-180 atoms) during the deformation. The dendrite of the Ti50Zr20Nb12Cu5Be13 BMGC has been well spheroidized and undergoes severe plasticity deformation after the deformation in the dendrite softening region.