Optimal cutting conditions when dry end milling the aeroengine material Ti–6242S

Through the experimental work on dry end milling of titanium alloy Ti–6242S, the extended Taylor model is resulted (TVc3.3×fz2.97×aa2.80=1.531×106) for characterizing the performance of the off-centre ball end milling alloyed carbide tool (W–(Ti/Ta/Nb)C–Co). Further analysis on the model results the optimum cutting conditions (Vc = 88 m/min at fz = 0.20 mm/tooth, Vc = 113.5 m/min at fz = 0.15 mm/tooth, and Vc = 163 m/min at fz = 0.10 mm/tooth) as the best compromise among cutting speed, material removal rate (cm3/min) and tool life (min). Moreover, it can be interpreted that the tool failure mode, tool wear mechanism and the behaviour of tool performance are changing at the optimum cutting conditions given by the model. By utilizing the FEM simulation, the chip morphology, contact length at the tool–chip interface and the tribological aspects (temperature, pressure) in machining at the optimum cutting conditions can be evaluated. The results of simulation support the interpretation of experimental results.