Strain-rate effect on yielding behavior of an in-situ Ti-based metallic glass matrix composite upon dynamic compression

摘要

An in-situ Ti-based metallic glass matrix composite, Ti_(43)Zr_(32)Ni_6Ta_5Be_(14), presents strain hardening and plastic flow upon dynamic compression. The strain hardening is mainly attributed to the competition between the dislocation mechanism within the crystalline dendrites and the thermal and structural softening mechanisms within the glass matrix. The plasticity of the composite is semi-quantitatively analyzed by the difference in shear band toughness between the glass matrix and crystalline dendrites. Furthermore, strain-rate effect on yield strength is characterized by employing the dislocation-based Zerilli and Armstrong (ZA) model, the cooperative shear model (CSM) associated with the adiabatic temperature rise in the shear transformation zone (STZ), together with the modified CSM model related to viscosity, respectively.