Characteristics of ultrasonic vibration-assisted ductile mode cutting of tungsten carbide

Abstract

In this study, investigations were carried out to evaluate the characteristics of ultrasonic vibration-assisted cutting of tungsten carbide material using a CNC lathe with CBN tool inserts. The cutting forces were measured using a three-component dynamometer, and the machined workpiece surfaces and chip formation were examined using a SEM. The experimental results showed that the radial force F x was much larger than the tangential force F z and axial force F y . The SEM observations on the machined workpiece surfaces and chip formation indicated that the critical condition for ductile mode cutting of tungsten carbide was mainly the maximum undeformed chip thickness when the tool cutting edge radius was fixed, that is, the ductile mode cutting can be achieved when the maximum undeformed chip thickness was smaller than a critical value. Corresponding to the chip formation mode (ductile or brittle), three types of the machined workpiece surfaces were obtained: fracture free surface, semi-fractured surface and fractured surface. It was also found that the cutting speed has no significant effect on the ductile chip formation mode.