Study of Work Hardening of SiCp/Al Composites in Vibration-Assisted Cutting Process Based on Molecular Dynamics

In order to study the work hardening phenomenon of machined surface in vibration-assisted cutting SiCp/Al composites materials using diamond tools, molecular dynamics methods were used in this study to establish a vibration cutting simulation model of SiCp/Al composites. The mechanism of work hardening of SiCp/Al composites is discussed by analyzing the slip and expansion of dislocations inside the workpiece, the obstruction of dislocations of SiC particles, and the interaction between dislocations. The impact of vibration-assisted cutting on internal work hardening of the workpiece was analyzed by comparing the variation of cutting force, internal dislocation density, and distribution of the workpiece under normal cutting and vibration cutting. The results show that in the cutting process, the presence of obstacle SiC particles will change the slip path of the dislocation, and the phenomenon of pinning points. “V” type dislocations, dislocation entanglements, and dislocation plugging formed inside the workpiece will aggravate the plastic deformation of the crystal, resulting in the generation of work hardening. The cutting force and dislocation density during vibration-assisted cutting are lower than that of normal cutting, and intermittent cutting significantly reduces the work hardening of the workpiece.