Applying the Taguchi Method for Optimization of Cutting Parameters of Aluminum Alloy Using Novel Bio-Degradable Oil as a Lubricant

The properties of cutting fluids play a critical role in lubricating and cooling in machining operations. This study describes the optimization of the cutting parameters (depth of cut, feed, and cutting speed) in a conventional lathe machine to reduce surface roughness of aluminum alloy 6061 by using a novel biodegradable oil as cutting fluid. The optimal cutting parameters for surface roughness in turning are determined by applying the Taguchi technique L-27 orthogonal array, and corresponding surface roughness is measured. Analysis of variance (ANOVA) results explained that feed is the most influential factor on surface roughness with a contribution of 29.67%, followed by speed, 24.82%, and coolant ratio, 22.86%, while the depth of cut makes the lowest contribution of 16.83%. The surface roughness is found at its lower level at a blend ratio of MO/CO 80/20%, then linearly increases at MO/CO of 90/10%, and the highest surface roughness is obtained when 100/00% mineral-based cutting oil is used as a coolant. The decrease in surface roughness is ascribed to the superior lubricating and cooling capabilities of castor oil. The confirmatory experimental value of surface roughness at the optimal setting is 0.202 µm, confirming the parameters’ optimization at this configuration.