Strain Rate Dependence Of Mechanical Behaviour In A Cuzr-Based Bulk Metallic Glass Composite Containing B2-Cuzr Phase

Strain rate on the mechanical behaviour of a Cu48Zr48Al4 bulk metallic glass composite containing a B2-CuZr phase was investigated under quasi-static and dynamic compression. It was found that the CuZr-based BMGC exhibits remarkable strain-rate-softening, although the deformation-induced matensitic transformation of the B2-CuZr phase similarly occurred under both quasi-static and dynamitic loading. The significant transformation-induced plasticity (TRIP) and pronounced work hardening characteristic of the BMGC upon quasi-static loading were found to be considerably deteriorated under dynamic loading. Furthermore the BMGC alloy was aboratively heat-treated into austenite and martensite states mainly containing the B2-CuZr phase and the B10-CuZr phase respectively. By comparing the strain rage responses of the mechanical behaviours in the austenite and martensite states, it was shown that the B2-CuZr phase itself presents dynamic softening due to the deformation-induced martensitic transformation with heat release effect.