Static and Dynamic Deformation of Metallic Glass and Its Composite - Constitutive Modelling and Experimental Investigation

Abstract

The mechanical behaviour of bulk metallic glass (BMG) and bulk metallic glass composite (BMGC) under static and dynamic deformation at room temperature are studied, through constitutive modelling and experimental investigation. A large-deformation constitutive framework for BMG is introduced, and based on this, a non-local constitutive model is formulated to examine the size effect of small-volumes of metallic glass, and to investigate the cause of post-yield work-hardening and the ?smaller is stronger/weaker? phenomenon. Experiments are also conducted on recently-developed La-based BMGCs, to study the influence of degree of crystallinity and strain rate. A large-deformation rate-independent constitutive model, based on the framework established, is proposed. Finally, the fracture behaviour of La-based BMG for static and dynamic loading is investigated, and the temperature evolution within a shear band at fracture is estimated. The findings have potential application in BMG/BMGC design and usage.