LAUSR

Heat dissipation is a foremost issue in machining of materials and to overcome this different cooling techniques are adopted to improve the surface integrity and diminish microstructural damage and to effectively flush chips produced. In this research, machinability of titanium grade 5 (Ti-6Al-4V) was carried out through drilling process considering three different cooling procedures like cryogenic cooling (CO2), palm oil based minimum quantity lubrication (MQL) and wet/flood cooling with general cutting fluid (emulsifiers). Experiments were prearranged in par with Taguchi’s technique and a suitable L18 orthogonal array was formulated and the outputs obtained viz., interface temperature and cutting forces (torque/thrust force) were analyzed by adopting response surface methodology (RSM). For interface temperature, type of coolant is the most influencing factor, whereas for cutting forces, the impact of feed rate, drill speed and type of coolant are significant. Response surfaces were fitted for the outputs and subsequently a higher polynominal regression equation was developed for prediction. The optimum condition obtained for constraint multiobjective optimization using desirability approach was: drill speed of 42.49 m/min, feed rate of 0.05 mm/rev and cooling type as cryogenic cooling. The main objecive is to minimize the interface temperature and torque subjected to the constraint thrust force (≤1500 N). Confirmation experiment performed with optimum condition displays a significant enhancement in output results.