Tensile fracture morphologies of bulk metallic glass

Abstract

The fracture morphology plays a much important role not only for the failure analysis of materials but also for the clarification of their fracture mechanisms. However, quantitative analysis of the fracture morphology of bulk metallic glasses (BMGs) is still very lacking. In this study, both model and mechanical experiments were conducted to reveal the development of the fracture morphology and the effect of stress state. Inclined notch tensile specimens of a Zr-based BMG with different notch angles were designed to obtain various stress states. For the first time, some new parameters to describe the tensile fracture surfaces of the BMG specimens were proposed. Statistical analysis of these parameters shows that the stress state has a significant influence on the features of fracture surfaces. Through a discussion on the structure and heat evolution during tensile deformation, two damage mechanisms associated with thermal softening and weakening by defects are found to have a combined effect on the tensile fracture of BMG.