Machining mechanism of polycrystalline nickel-based alloy under ultrasonic elliptical vibration-assisted cutting

Abstract

This work investigates the machining mechanism and deformation behavior of NiFeCo under conventional nanoscale cutting and ultrasonic elliptical vibration-assisted cutting (UEVC) through molecular dynamics simulation. The material removal process is considered in various vibration frequencies, amplitude ratios, and phase angles. In both cases, the highest shear strain, local stress, and temperature atoms are primarily located in the cutting area and chip volume, but the magnitudes are more significant under UEVC. The distribution analysis results of stacking fault and dislocation also show that grain boundaries strongly influence the deformation behavior and the local stress in the material. Moreover, in the cases of UEVC, the rise of vibration frequency and the decrease in amplitude ratio positively impact improving the material removal rate and reducing the average cutting force. Meanwhile, the change in phase angles affects only the timing of the peak in force value and has no significant effect on the resultant force and the cutting efficiency.