Abstract
In order to improve the machinability of SiCp/Al composites and reduce the surface defects after machining, a laser coupled ultrasonic vibration-assisted turning (LA-UVAT) method is proposed. In order to study the mechanism of material deformation and surface formation in LA-UVAT, a finite element model of LA-UVAT was established, and the Johnson-Cook equations containing the strain gradient were programmed into the user subroutine VUMAT by the programming language through the secondary development of ABAQUS, and then imported into ABAQUS for simulation. Combining the simulation and experimental results, the influence of the temperature, stress, and dislocation motion in 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 depends on their position relative to the tool. The surface quality of LA-UVAT is better compared to conventional machining, with fewer broken particles and defects on the machined surface. The simulation results are in good agreement with the cutting experiment results. Therefore, LA-UVAT can be used for efficient machining of SiCp/Al composites.