Tool Life and Surface Roughness in Dry High Speed Milling of Aluminum Alloy 7075-T6 Using Bull Nose Carbide Insert

Abstract

The paper reports the findings of the experimental work to study the impact of machining parameters, particularly cutting speed, feed rate, and axial depth of cut towards cutting tool life and machined surface roughness in high-speed milling aluminium alloy 7075-T6 with bullnose cutter under dry environment. Previous studies found that tool life and surface roughness in machining aluminium alloy 7075-T6 using cemented carbide are unfavourable compared to other materials. However, this observation needs further study. Thus, a raw block of aluminium alloy 7075-T6 was proposed in this experiment. An eight-run experiment was designed according to full factorial design based on two levels of cutting speed (500 m/min, 600 m/min), feed rate (0.12 mm/tooth, 0.15 mm/tooth), and axial depth of cut (1.40 mm, 1.70 mm) and then analysed employed ANOVA. Cutting tool life was restricted by tool wear in the milling process. The microscope and portable surface roughness tester were employed to analyse tool wear and average surface roughness value. Cutting speed and feed rate were found to be a significant factor to the tool life and surface roughness. The longest tool lifespan of 16.79 minutes and lowest surface roughness value of 0.595 µm were determined at a speed of 500 and 600 m/min, respectively, with a low combination of the rest of parameter, which are 0.12 mm/tooth and 1.40 mm.