Investigation on cutting mechanisms of machining SiCp/Al based on strain gradient theory

Aluminum-based silicon carbide composites (SiCp/Al) are classified as typically difficult-to-machine materials due to severe tool wear, premature tool failure, and surface defects. A deep understanding of the cutting process of particle-reinforced aluminum-based composites is of great significance for better application of this composite material. This article adopts the method of multiphase modeling, and through the secondary development of commercial simulation software ABAQUS, the Johnson-Cook constitutive equation containing strain gradient and the B-W fracture criterion describing fracture are programmed into the user subroutine VUMAT using programming language, and then imported into ABAQUS for simulation. Combining the experimental as well as simulation results, the dislocation movement of the two phases of SiCp/Al during machining process was studied from the perspective of material dislocation motion, and the mechanism of surface topography and chip formation were investigated. The effect of temperature change in the cutting process and the effect of cutting temperature on the machined surface and chips were also investigated. It is found that the results obtained using the modified constitutive model and fracture model were in better agreement with the experimental results.