A mechanics-based predictive model for chip breaking in metal machining and its validation

In metal cutting, effective chip breaking enables efficient chip removal, prevents workpiece and tool damage, and provides operational safety. Currently available cutting tool insert designs often neglect the underlying physics of chip breaking process governed by ductile fracture on the chip free-surface. This paper presents a predictive model for chip breaking in turning operations, which combines a mechanics-based model, utilizing a ductile fracture criterion, with a finite element model. Experimental validation on aluminum alloy AA7075-T6511 and brass CuZn38As shows that the impacts of the tool and process parameters on chip breakability could be accurately predicted without prior knowledge of the ductile material properties.