Improving plasticity and work-hardening capability of β-type bulk metallic glass composites by destabilizing β phases

Ti/Zr-based bulk metallic glass composites (BMGCs) containing an in-situ formed β phase (β-type BMGCs) normally show a poor work-hardening capability or even work-softening during plastic deformation. The limited work-hardening capability of the β phase by the entanglement of dislocations cannot totally compensate the shear softening of the glassy matrix. In this work, a strategy is proposed to destabilize the β phase, and the BMGC containing a metastable β phase (metastable β-type BMGC) shows improved plasticity and work-hardening capability due to the deformation-induced phase transformation from β-Ti to α″-Ti. The underlying principle for destabilizing β phases in BMGCs by adjusting the overall compositions and the structural origins for the improved plasticity and work-hardening capability of metastable β-type BMGCs are discussed. These findings shed light on developing metastable β-type BMGCs with excellent mechanical properties.