Optimizing Surface Finish in Face Milling of Aluminium Alloy Al 6061: An Experimental Analysis of Cutting Speed and Depth of Cut

Abstract

Surface quality in machining is predominantly influenced by cutting parameters, specifically cutting speed and depth of cut. This study investigates the effect of these parameters on the surface roughness of Aluminium Alloy 6061 during face milling utilizing an HSS cutter. A conventional Schaublin 13.2 milling machine was employed for the experiments. The cutting speed (Vc) was varied at 80, 150, and 200 m/min, combined with a depth of cut (a) of 0.75, 1.00, and 1.25 mm. Nine specimens were machined based on a full factorial experimental design. Surface roughness (Ra) was measured and classified according to international standards (ISO). The results demonstrate that higher cutting speeds generally yield superior surface finish. The optimal surface roughness was achieved at a cutting speed of 200 m/min and a depth of cut of 1.00 mm, resulting in an Ra value of 0.65 µm (N5 classification). Conversely, the highest roughness was observed at the lowest cutting speed (80 m/min) and highest depth of cut (1.25 mm), with an Ra value of 2.36 µm (N7). This study concludes that selecting appropriate cutting parameters is critical for achieving the desired surface quality in the machining of Al 6061, with cutting speed being the more influential factor