Stabilizing machining processes of high-strength materials by suppressing chip segmentation

Machining high-strength alloys frequently leads to segmented chip formation due to severe thermo-mechanical loading in the primary shear zone. The resulting process vibrations increase tool wear and degrade surface quality. This study investigates an approach for stabilization of machining processes through suppression of segmented chip formation under production-relevant cutting parameters by locally limiting chip space using a counter body, the Constraint tool. Therefore, orthogonal cutting experiments are conducted to characterize unconstrained chip formation process and associated tool loads as well as deflections due to chip segmentation during machining of titanium alloy Ti6Al4V. In addition, finite element simulations that reliably predict segmented chip formation are used for a systematic variation of edge shape and positioning of the Constraint. Optimal configurations that suppress macroscopic chip segmentation are identified and transferred into physical Constraint designs. These are manufactured using wet abrasive jet machining and validated in orthogonal cutting experiments using a custom clamping and positioning setup. A final comparison between constrained and unconstrained cutting conditions quantifies the degree of segmentation suppression. Subsequently, the results obtained are used to check the transferability to steel alloy 51CrV4.