Effectiveness of Near Dry Machining on Tool Performance in Bull Nose Milling of Aluminum Alloy 7075 T6

Abstract

The paper investigated the effectiveness of near-dry machining also known as minimum quantity lubrication (MQL) on tool wear when aluminum alloy 7075-T6 was milled using bull nose carbide insert. The foregoing study found that the high tool wear was occurred in machining aluminum alloy 7075-T6 with uncoated carbide under dry machining. Due to that, dry machining was performed to examine its result with MQL. Different values of cutting parameter selected were cutting speed of 500 and 600 m/min, the feed rate of 0.12 and 0.15 mm/tooth, and axial depth of cut of 1.40 and 1.70 mm. 100 mL/h was set as MQL flow rate. Eight samples were performed on five axes milling machine according to a full factorial design. The tool wear was examined and measured progressively at every time interval using an optical microscope. From the analysis, MQL 100 mL/h at 500 m/min, 0.12 mm/tooth, and 1.40 mm was found to be better than dry machining. The adhesion wear mechanism was observed at both machining conditions. Near-dry machining with appropriate flow rate and machining parameters has the potential to contribute to long-term environmental friendly machining in line with the industrial revolution phase.