Research on machining mechanism of SiCp/Al composites based on three-dimensional equivalent model

The SiCp/Al composites exhibit stable mechanical properties, good electrical conductivity, and thermal conductivity, making them widely used in high-performance components in aerospace and other fields. In order to better understand the cutting mechanisms of SiCp/Al composites, this study addresses the challenge of establishing a Three-Dimensional (3D) model for multiphase materials in finite element analysis. A constitutive model for SiCp/Al composites is defined, considering both the SiC particle reinforcement effect and damage characteristics, thereby establishing a 3D finite element simulation model through the development of an Abaqus user subroutine for equivalent homogenization. By integrating simulation and experimental data, the spatial distribution patterns of the primary shear zone (PSZ) and the subsurface stress fields under various cutting parameters are analyzed, alongside their influence on material removal mechanisms. The research findings indicate that the stress in the PSZ includes four stages: accumulation at the cutting edge, expansion, stabilization at the maximum value, and gradual reduction following slip. It is observed that the maximum stress occurs at the main shear plane, with SiC particle damage more likely to occur at both ends of the chip. Furthermore, the Von Mises stress within the machined subsurface decreases with increasing cutting speed and increases with greater cutting depth, while the stress near the surface of the workpiece remains relatively high even at small cutting depths. In order to minimize the machining damage to the sub-surface, it is recommended to use a larger cutting speed and a smaller cutting depth.