Machinability improvement investigation in face milling of Ti–3Al–2.5V alloys using TiAlN coated carbide insert under dual nozzle minimum quantity lubrication cooling environment

This research presents the machinability analysis in face milling of Ti–3Al–2.5V alloys using TiAlN-coated carbide insert under dual nozzle minimum quantity lubrication (MQL) cooling conditions. The TiAlN-coated insert has several favorable characteristics like superior wear resistance, greater hardness, and high chemical stability at elevated temperatures. The performance capability of this cutting insert was assessed using machinability responses such as surface roughness, tool wear, and cutting temperature results. The improved quality finish was found with maximum Ra (0.823 µm) while the improved accuracy of flatness (0.044) was obtained even though the rotational speed of the face mill cutter (N) was highest (1500 r/min). Likewise, an acceptable range of flank wear (0.058–0.118 mm) and a lower range of cutting temperature (65 °C–106.8 °C) was found due to the superior thermal characteristics of TiAlN coating, effective cooling, and lubricating capability of the dual nozzle MQL system in face milling to this alloy. Further, by using the entropy coupled multi-objective optimization ratio analysis method, the optimal value of milling parameters was computed as coolant flow rate (Q) 50 ml/h, feed speed (vf) 200 mm/min, and rotational speed of the face mill cutter (N) 500 r/min. At this optimal setting, the optimum Ra, VBc, and T were found as Ra = 0.596 µm; VBc = 0.058 mm, and T = 65 °C, respectively.