Modeling of chip-tool interface friction to predict cutting forces in machining of Al/SiCp composites

摘要

In Al/SiCp metal matrix composites, in addition to machine, tool and process-related parameters, a change in composition (size and volume fraction of reinforcement) has a influence on machining force components. In the analytical models in the literature, the effect of abrasive reinforcement particles, which affects the coefficient of friction and consequently the friction angle, has not been considered while predicting cutting forces in machining of MMCs. In this paper, chip-tool interface friction in machining of Al/SiCp composites has been considered to involve two-body abrasion and three-body rolling caused due to presence of reinforcements in composites. The model evaluates resulting coefficient of friction to predict the cutting forces during machining of Al/SiCp composites using theory of oblique cutting. Further, the model considers various frictional forces on the wiper geometry on the cutting edge that has been found to improve the integrity of machined surface on composites. The predicted cutting force values were found to agree well with the corresponding experimental values for finer reinforcements composites with the assumption that 40% of the reinforcement particles contribute to the abrasion at chip-tool interface. However, for the coarser reinforcement composites, assumption that the 60% of the particles contribute to the abrasion yields better results.