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 710K ranges from 1.6nm³ to 2.5nm³ under compressive tests and 1.0nm³ to 2.7nm³ 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.