Influence of cutting speed and cooling method on the machinability of commercially pure titanium (CP-Ti) grade II

The present investigation aims in highlighting the influence of cutting speed and an eco-friendly cooling technique during finish turning of CP-Ti grade 2. Experiments were performed at three distinct machining modes viz. dry cutting (DC), flood cooling (FC) and minimum quantity lubrication (MQL) using carbide inserts. Water soluble oil and vegetable oil were used as cutting fluids with FC and MQL respectively. The work material was turned at three different cutting speeds i.e. 51, 67 and 87 m/min whereas feed rate and depth of cut were kept as constant at 0.12 mm/rev and 0.5 mm respectively. A comprehensive exploration on the cooling effects of vegetable oil based MQL method on some of the key machinability aspects such as cutting force, tool wear, friction coefficient, chip morphology, chip reduction coefficient, micro hardness of machined surface, surface roughness and machining temperature is reported. The aforesaid turning responses were recorded and compared in order to exhibit the feasibility of MQL approach in comparison with dry and flood cooling approach. The results obtained during the investigation clearly established the superiority of implementing MQL for achieving improved machinability within a specified range of process parameters.