Prediction and Verification of Cutting Force in Machining of SiCp/Al Composites Based on Dynamic Mechanical Characteristics of Cutting Deformation Zone

Metal matrix composites (MMCs) reinforced by ceramic particles have been gradually applied in modern industry because of their excellent mechanical characteristics. However, the addition of high hardness particles also produces a significant challenge for machining of MMCs. Cutting force characterizes the dynamic mechanical characteristics of cutting deformation zone by reflecting the interaction of tool-workpiece, which is of great significance to describe the machinability of MMCs. This paper aims to propose a geometric model of cutting force to predict the cutting force and monitor the cutting state during machining of SiCp/Al composites. The shear deformation force, friction force in tool-chip interface and ploughing force in tool-workpiece interface, corresponding to shear deformation zone (plastic deformation of Al matrix mainly), fraction zone (tool-chip interaction) and ploughing zone (tool-workpiece interaction and fracture and debonding of SiC particles) were considered in predicted model. Meanwhile, the influence of tool cutting edge radius was considered. The results obtained by systematic cutting experiment with different cutting conditions were compared with predicted results, and the maximum error between predicted and measured value was within 12%, indicating the validity of predicted model in machining of SiCp/Al composites. With the increase of cutting depth (0.1 mm-1.5 mm), the roughness of machined surface increased from 149 to 377 nm, which can be explained by a larger deformation resistance caused by a deeper cutting depth. In addition, the applicability of the proposed model under different volume fraction of SiCp/Al composites were studied, and the maximum error between predicted and measured value is within 5%.