Towards sustainable manufacturing: Multiple optimization of surface roughness Ra, flank wear Vb in MQL-assisted milling of Titanium Alloy Ti-6Al-4V

Abstract

This research focuses on the sustainable optimization of the milling process for Titanium Alloy Ti-6Al-4V using Minimum Quantity Lubrication (MQL) assistance. This experimental research investigates the effects of cutting parameters and lubrication conditions on the surface roughness ([Formula: see text]) and flank wear ([Formula: see text]) in the milling process of Titanium Alloy Ti-6Al-4V. The study aims to evaluate the influence of cutting speed ([Formula: see text]), feed rate ([Formula: see text]) and depth of cut ([Formula: see text]) on the selected machining performance indicators. The experiments were carried out using a DMG Mori Seiki DMU50 CNC center, and the workpiece samples were measured at [Formula: see text]. Three different lubrication conditions were employed, including dry machining, conventional flood cooling and Minimum Quantity Lubrication (MQL) using peanut oil. The cutting parameters were varied based on a Taguchi L9 orthogonal array design to explore the main effects of each parameter on [Formula: see text] and [Formula: see text]. The results reveal that cutting speed ([Formula: see text]) has the most significant influence on surface roughness, followed by feed rate ([Formula: see text]), while the impact of depth of cut ([Formula: see text] is negligible in comparison. Conversely, the coolant mode has the most significant impact on flank wear ([Formula: see text]), followed by feed rate ([Formula: see text]) and depth of cut ([Formula: see text]), while the influence of cutting speed ([Formula: see text] is relatively minor. Under the same cutting parameters, transitioning from dry machining to MQL led to a sharp decrease in [Formula: see text] from 170 to 100[Formula: see text][Formula: see text]m, and it increased to approximately 145[Formula: see text][Formula: see text]m when switching to flood cooling. Additionally, increasing the feed rate from 0.02 to 0.06[Formula: see text]mm/tooth reduced [Formula: see text] from around 135 to 120[Formula: see text][Formula: see text]m, but it significantly rose to approximately 165[Formula: see text][Formula: see text]m when the feed rate was further increased. Furthermore, the application of MQL with peanut oil as a lubricant and coolant demonstrated improvements in surface finish and reduced tool wear compared to dry and conventional flood cooling. The MQL approach led to better machining performance with lower [Formula: see text] and [Formula: see text] values. Overall, this study provides valuable insights into the effects of cutting parameters and lubrication conditions on surface roughness and flank wear in the milling process of Titanium Alloy Ti-6Al-4V. The findings offer practical guidelines for optimizing machining conditions to achieve desired surface quality and extend tool life while considering the environmental benefits of employing MQL in the manufacturing process.