Effect of cutting speed on surface integrity and chip formation in micro-cutting of Zr-based bulk metallic glass

Single-shear plane theory is an effective tool for understanding the cutting mechanisms of conventional and precision machining. This study investigates the formation of multiple shear bands in micro-cutting of zirconium-based bulk metallic glass (BMG) where classic models have not been studied. A series of slip steps were observed in the cutting direction which was significantly affected by cutting speed. Surface roughness of the machined surface in micro-cutting BMG was found to be sensitive to the cutting speed. Electron microscopy studies further confirmed the mechanism of the micro-cutting-induced nanocrystallization with the formation of shear bands within the primary deformation zone in the micro-cutting process under various cutting speeds. This work contributes to demonstrating the effects of cutting speed on the formation of the shear band and the serrated flow behavior under complex loading and boundary conditions in micro-cutting.