Multi-step cutting depth optimization method based on the removal mechanism of SiCp/Al

SiCp/Al composites (Silicon Carbide Particles embedded in an Aluminum matrix) are widely used in aerospace, automotive and other fields due to their excellent properties such as high dimensional stability and high specific strength. But, the large hardness of SiCp particles makes the processing of SiCp/Al difficult .The position of SiC particles relative to the cutting path determines the interaction between the tool and the particles, which affects the cutting process of SiCp/Al. However, there is a lack of study on the position of SiC particles relative to the cutting path. We study the processing mechanism of SiCp / Al under multistep cutting and propose a model of the relative position of the cutting path and the SiCp particle. To reduce particle damage during the cutting process, a quantitative relationship between cutting depth and the diameter of SiC particles is established for the first time in this paper. Finite element models considering particle shape, distribution, and cohesive element are established based on the above model. The particle removal mechanisms, cutting force characteristics, and surface quality are compared in detail for multi-step and single-step cutting. The simulation model is validated through experiment. The results show that the optimized multi-step cutting parameters can change the removal mode of particles from overall debonding to local fracture, effectively reduce the machining defects, and finally improve the surface quality of the workpiece. The Ra and SSD depths are reduced by 41.1% and 27.9%, respectively, when compared to single-step cutting.