Effect of Water Oil Mist Spray (WOMS) Cooling on Drilling of Ti6Al4V Alloy Using Ester Oil Based Cutting Fluid

This paper explains environment friendly water oil mist spray (WOMS) cooling method which is used to obtain lower cutting temperature and higher lubrication at tool chip interface during Ti6Al4V twist drilling process. WOMS is Ester oil based minimum quantity lubrication (MQL) technique but different than neat oil or straight oil based MQL techniques due to combined application of water and oil. Drilling experiments at maximum cutting speed of 50 m/min and 167mm3/s material removal rate (MRR), using a 8mm diameter TiAlN coated solid carbide twist drill are conducted under dry machining and WOMS cooling environment. The effect of WOMS are mainly discussed with different cutting parameters, twist drill geometry and compared with dry cutting conditions. A comprehensive evaluation on the cooling effects of WOMS was carried out by spray characterization and subsequent drilling tests. This work is focused on the combined study of tool wear evolution, drill geometry, quality of machined holes under WOMS cooling environment. Drilling under WOMS condition observed 66% higher tool life than dry cutting environment. Experimental results indicated that drilling under WOMS cooling had better cooling effects, higher tool life, optimum cutting parameters.