Prediction of chip formation and cutting forces in flat end milling: Comparison of process simulations with experiments

This study is part of the ongoing research at ERC/NSM on the investigation of high speed milling processes for machining dies and molds. A special flat end milling operation, using a single insert indexable tool with a straight cutting edge (i.e. zero helix angle), was selected to investigate chip formation in milling. Dry milling of P-20 mold steel using a plain tungsten carbide (WC) cutter was simulated for selected cutting conditions (cutter diameter: 15.88 mm, cutting speeds: 50, 100 and 200 m/min, feeds: 0.1 and 0.155 mm/tooth, axial depth of cut: 1 mm, and radial depth of cut: 15.88 mm). Chip formation, cutting temperatures, tool stresses and cutting forces were predicted from Finite Element Method (FEM) simulations. The experiments were conducted in a horizontal high speed milling center to measure cutting forces. Predicted cutting forces and chip shapes were compared with experimental results. This study demonstrates the effectiveness of FEM simulations in predicting process variables in a simple flat end milling operation.