Optimization of cutting parameters for finish turning of 6082-T6 aluminum alloy under dry and RQL conditions

Cutting parameters have a significant influence on the surface finish after turning, which can generate unwanted surface roughness. Thus, the parameters optimization could be a favorable strategy to improve the machined part quality. Therefore, the optimization of the cutting speed (vc), feed rate (f) and depth of cut (ap) on finish turning of 6082-T6 aluminum alloy using an uncoated carbide tool (positive rake angles and 0.4 mm tip radius) under dry and reduced quantity lubricant (RQL) conditions was performed. The input variables were combined and randomized via Box–Behnken design of experiments. The surface roughness profiles were recorded, and the roughness parameters Ra and Rz were measured in each combination of parameters. After optimization, the best results of Ra (0.44 μm) and Rz (2.73 μm) after dry machining were obtained with vc = 851 m/min, f = 0.07 mm/rev. and ap = 2 mm. Since RQL machining, the correspondent levels (vc = 403 m/min, f = 0.05 mm/rev., ap = 0.5 mm) resulted in the lowest values of Ra (0.18 μm) and Rz (0.96 μm). The RQL favored the chip formation in turning of AA6082-T6, minimized the occurrence of grooves (scratches), burrs and waviness on the machined surface and generated better surface quality.