Effect of minimum quantity lubrication and dry cutting on the tool life and chip morphology after milling of aluminum alloy 7075-T6

Abstract

This research deals the experimental works on the effect of minimum quantity lubrication (MQL) and dry cutting towards the cutting tool life and chip morphology in high-speed milling of aluminum alloy 7075-T6 with uncoated carbide tools. MQL and dry cutting were eco-friendly approaches that highlight essential issues in the field of manufacturing technology. Thus, further investigation required to observe the intensity of those approaches. The experiment was done on computer numerical control (CNC) five axes milling machine at distinct machining parameters, which are cutting speed (500 and 600 m/min), feed rate (0.12 and 0.15 mm/tooth) and axial depth of cut (1.4 and 1.7 mm), while the radial depth of cut restricted to 7 mm. The effect of fluid approaches and machining parameters on eight samples have analyzed the result of the setting of three factors and two levels in accordance with the full factorial design and analyzed further using ANOVA. The MQL flow rate was set at 100 mL/h. The tool life criterion was determined when the tool wear failure reached 0.30 mm. The chips collected from all machining conditions were taken to be examined using an optical microscope. The empirical model of tool life for the MQL and dry cutting has been developed within the experimental ranges evaluated. The prolonged tool lifespan beyond 20.14 minutes and favorable chip formation were obtained at 500 and 600 m/min, 0.12 mm/tooth, and 1.40 mm, respectively under MQL 100 mL/h. MQL 100 mL/h appeared to be one fit for metal cutting industry that prioritizes clean and green machining as well as the use of appropriate machining parameters as it leads to economic benefits in terms of fluid cost-saving and the better machinability.