Study of Deformation Mechanism and Surface Formation of Laser Coupled Ultrasonic Vibration-Assisted Turning of SiCp/Al Composites

Abstract

In order to enhance the machinability of SiCp/Al composites and improve the surface quality after machining, a laser-ultrasonic vibration-assisted machining (LA-UVAM) method is presented. In order to investigate the deformation mechanism in the material and the mechanism of surface formation in LA-UVAM, a finite element model of LA-UVAM was established. Using the secondary development imported into abaqus, the Johnson–Cook principal equations containing strain gradients were programmed into the user subroutine VUMAT for simulation. Combining the simulation and experimental results, the influence of dislocation motion in the temperature, stress, and strain gradient effects on cutting deformation during SiCp/Al composite machining was analyzed from the perspective of material dislocation theory. The results show that the presence of SiC particles changes the microstructure of the matrix material and induces high strain gradients in the matrix. In addition, the damage of the particles is closely related to their relative position to the tool. LA-UVAM significantly improves the surface quality with fewer broken particles and defects on the machined surface compared to the conventional machining method. The simulation results are in good agreement with the cutting experiment results. Therefore, LA-UVAM can be used for the efficient machining of SiCp/Al composites.