Different deformation behaviors of two in-situ Ti-based metallic glass matrix composites upon quasi-static and dynamic compressions

Two kinds of in-situ Ti-based metallic glass matrix composites, Ti40:Ti40Zr24V12Cu5Be19 (at%) and Ti48:Ti48Zr18V12Cu5Be17 (at%), containing ductile dendrites are fabricated. Quasi-static and dynamic compression behaviors of the composites are investigated. Upon quasi-static compression, the Ti40 composite exhibits brittle fracture because the fine dendrites cannot retard the propagation of shear bands. In contrast, macroscopic plasticity is available for the Ti48 composite due to plastic deformation of the coarse dendrites and effective obstruction to the propagation of shear bands. Upon dynamic compression, the fracture strain of the Ti48 composite decreases due to the insufficient time for multiplication of shear bands. The strain-rate sensitivity exponent of the Ti40 composite is calculated. The Johnson-Cook (J-C) plasticity model is employed to model the flow stress behavior of the Ti48 composite.