Study on the milling surface quality of 20% volume fraction SiCp/Al composites

During milling, brittle fracture occurs in SiCp/Al composites due to extrusion, while plastic deformation occurs in the aluminum matrix. The damage of particles and the matrix is different. In order to observe the brittle fracture process of particles more accurately, a single particle milling model was established to analyze the damage and deformation of particles when cutting along different positions. In the study of the influence of cutting speed on particle failure, a two-dimensional simulation model with multi-particle random distribution was established. Keeping the cutting depth the same, only the cutting speed was varied to study its effect on the surface quality. Detailed analysis of the orthogonal test results shows that the influence on surface quality is from feed rate, milling speed, and milling depth in descending order. The optimal cutting conditions are milling speed of 47.10 m/min, feed speed of 10 mm/min, and cutting depth of 80 μm. Through the analysis of sub-surface morphology, the main causes of cracks, pits, and other defects on machined surfaces can be explained, and the experimental results are proved to be the same as the simulation results.