Effects of process parameters on periodic impact force exerting on cutting tool in ultrasonic vibration-assisted oblique turning

During ultrasonic vibration-assisted machining, the large impact force induced by tool-workpiece re-engagement (TWR) is an important factor that affects tool chipping. However, mechanical analysis into process factors that affect the impact force and their influencing mechanisms are insufficient. Herein, a prediction model for the instantaneous cutting force during both TWR and the stable turning process, which depends on the process parameters and material properties, is firstly proposed based on the kinematic and dynamic analysis of ultrasonic vibration-assisted oblique turning (UVAOT). The results calculated using the developed cutting force model agree well with the experimental results presented in the literature. Next, the linear change law of the instantaneous cutting force with cutting time during the actual TWR is clarified using the proposed model. The effect of the UVAOT process parameters on the average impact force during the periodic TWR process is discussed, and the influence mechanism is analyzed from the perspective of mechanics. A positive linear correlation is discovered between the feed speed and average impact force. The ultrasonic amplitude and cutting speed do not significantly affect the average impact force of the new sharp cutting tools. These findings are consistent with the experimental observations of tool chipping and are applicable to select process parameters for reducing tool chipping during UVAOT.

Automated summary

This study proposed a prediction model for the instantaneous cutting force during ultrasonic vibration-assisted machining, analyzed the linear change law of cutting force with cutting time, discussed the influence of process parameters on impact force, and found a positive linear correlation between feed speed and average impact force.