Strain rate response of a Ti-based metallic glass composite at cryogenic temperature

Quasi-static and dynamic deformation behavior of a Ti₄₈Zr ₂₀Nb₁₂Cu₅Be₁₅ bulk-metallic-glass composite (BMGC) were investigated at cryogenic temperature (77 K). Results demonstrate that the composite shows good plasticity at quasi-static deformation, but brittle fracture occurs during dynamic deformation. Compared with quasi-static deformation which is insensitive to strain rate, dynamic deformation of the composites exhibits negative strain-rate response that the fracture strength decreases with increasing strain rate. The matrix is believed to dominate the strain-rate response of the present BMGC at cryogenic deformation. Thermal softening due to significant temperature rising in shear band is believed to be responsible for negative strain-rate response during dynamic deformation at cryogenic temperature.