Molecular dynamics simulation and experimental study of laser-assisted machining of SiCp/Al composites

Abstract

High-quality machining of SiCp/Al composite faces a number of challenges due to the presence of hard and brittle SiC particles, making it a typical difficult-to-machine material. Conventional machining (CM) inevitably leads to high cutting forces and poor surface quality, which significantly limit the potential applications of SiCp/Al composites. Laser-assisted machining (LAM) has been evidenced that it can remarkably improve the machinability of SiCp/Al composites, however, the microscopic removal mechanism of the material under the effect of laser remains to be investigated in depth. In this paper, the molecular dynamics (MD) simulation and Transmission Electron Microscope (TEM) experiments are employed to carry out further research. A MD model for LAM of SiCp/Al composites is established, which is applied to analyze the dynamic evolution of the cutting forces and the dislocations of the material during the machining. The results show that with the rise of laser power, the dislocation density inside the Al matrix decreases gradually. The coordinated deformation ability of SiCp/Al composites is enhanced, and the cutting force tends to decrease. The high consistency between experimental and simulation results verifies the validity of the MD model.