Analysis of flat-end milling forces considering chip formation process in high-speed cutting of Ti6Al4V titanium alloy

This paper proposes a unified numerical and analytical approach to predict flat-end milling forces considering the chip morphology and cutting force in high-speed cutting of titanium alloy (Ti6Al4V). A two-dimensional finite element (FE) model of the orthogonal cutting process is developed by applying a displacement-based ductile failure criterion. With this FE model, the segmented chip formation is analyzed. The mesh dimension is investigated as an effective factor in the chip segmentation. The numerical results demonstrate that the chip morphology is significantly affected from the mesh dimension while the average cutting force varies slightly with the mesh dimension. The mesh dependency of the chip morphology can be decreased by applying the non-local progressive damage model involving the intrinsic material length. An attempt is also made for modeling and prediction of cutting forces in high-speed flat-end milling. The milling force constants which are generally derived from experimental calibrations are required to predict the milling forces by using the unified mechanics of cutting approach. Here, the numerical FE simulations are carried out to characterize the milling force constants. The milling forces predicted analytically are validated by comparing with those obtained from the experimental study. Finally, the behavior of the milling forces can be effectively analyzed through the proposed approach based on the chip formation process.