Elastic and plastic chip deformation mechanism in 1D vibration-assisted metal cutting

Abstract

Both 1D and 2D vibration-assisted machining (VAM) are able to improve the cutting performance in micro cutting in terms of surface integrity, cutting force and tool wear. In 2D VAM, it has already been concluded that a lower nominal cutting speed or a smaller speed ratio will lead to a decreased chip compression ratio (CCR) due to the introduction of more reversed friction. However, in 1D VAM, the effect of speed ratio on the CCR has not been systematically studied yet. In this study, a low-frequency 1D VAM test is firstly conducted to understand the instantaneous chip deformation status and tool-chip contact condition in a vibration cycle, which is then broken into five elastic and plastic categories based on the measured force ratio and relative tool positions. Furthermore, ultrasonic 1D VAM tests are also conducted to evaluate the effect of speed ratio on the chip formation and the variation of CCR.