Simulation study on defect formation mechanism of the machined surface in milling of high volume fraction SiCp/Al composite

The surface quality of SiC particle-reinforced aluminum matrix (SiCp/Al) composite plays an important role in their practical performance. Therefore, an in-depth understanding of the defect formation mechanism paves the solid foundation for the improvement of machined surface quality, which is the prerequisite for the widespread application of SiCp/Al materials. In this paper, the geometrical analysis of milling process was conducted firstly. Then, two-dimensional meso-scale finite element models composed of hard SiC particles and soft aluminum matrix were established for investigating the milling process of the SiCp/Al composite. Both a randomly distributed circular SiC particles model and a polygon SiC particles model were built respectively with high volume fraction. The simulation result indicated that the rotation, pulling out, big cleavage, micro fracture, and cutting through of the SiC were the main defect formation mechanisms. The simulated machined surface morphology was compared with the profile of a milled surface, and a good correlation was obtained.