Low-speed orthogonal cutting of large Zr-based metallic glasses: A shear angle model considering internal friction and serrated chip formation

Metallic glasses have high hardness, low cutting force, and serrated chip formation, which pose significant challenges for cutting. The chip formation mechanism of metallic glasses under low-speed cutting has been studied, but the effects of compression and internal friction have been neglected. In this study, a shear angle model that considers internal friction was proposed and compared with classical shear angle models. Low-speed orthogonal cutting experiments on Zr-based metallic glasses were conducted and the cutting forces, chip morphology, shear angle, external and internal friction angle under different cutting parameters were measured and calculated. The results show that the internal friction angle ranges from 21.3° to 36.0° and the shear angle ranges from 29.9° to 38.0°. The improved model can better characterize the cutting properties of metallic glasses. This study presents a new method and model for low-speed cutting of metallic glasses and provides insights into their deformation and fracture behaviors.