Influence of tool vibration and cutting speeds on removal mechanism of SiCp/Al composites during ultrasonic elliptical vibration-assisted turning

Revealing the mechanical removal mechanism and improving the machinability of SiCp/Al composites is always demanding because of the diversity of mechanical properties between the plastic matrix and brittle reinforcement. As an effective processing method, ultrasonic elliptical vibration-assisted turning (UEVT) has been proven to enhance the machinability of difficult-to-machining material, but the impact of vibration effects on deformation behavior of SiCp/Al composites has not been accurately studied. This paper investigates the mechanical removal mechanism of SiCp/Al composites in UEVT compared with traditional cutting (TC), evaluates the influence of tool vibration and removal speeds on particle deformation by scratching tests. Different from TC, highdensity zone of broken particles dominates the surface morphology with low cutting speed in UEVT, which is conducive to reducing surface roughness. UEVT technology is beneficial to interrupt the continuous impact of particles on rake face, obtaining lower interface temperature and slighter tool wear. In addition, it is observed that the cluster stripping of Al matrix appears in removing of SiCp/Al composites by TC with high scratching speed, which has negatively influence on surface roughness and cutting edge integrity. Finally, a rational selection of cutting speed (200 mm/min) and UEVT technology are beneficial for the outstanding machinability of SiCp/Al composites. The interesting discoveries provide a significant theoretical basis and practical machining guidance for process optimization of cutting parameters to improving the machinability of SiCp/Al composites in UEVT.