Achieving Desired Machinability in Turning Using The Analytical Hierarchy Process

Machinability plays an important role in material working industries. A material with good machinability requires less force with improved tool life during machining to make a desired surface finish. However, improving productivity as well as finish often faces a big challenge to find appropriate machining conditions to achieve the same. Environment-friendliness is also to be considered. Multi-criteria decision-making (MCDM) method can play an important role to suggest suitable machining conditions in this respect. An experimental work is done on machinability study of hard AISI 4340 steel using different environment. Turning experiments are done using coated carbide inserts through small quantity lubrication (SQL) under different cutting velocity and feed. Dry, rice bran oil-based solution and alkaline solution are chosen to be the environmental conditions. Linder different machining conditions, types of chips, cutting force, surface roughness, etc. are noted. Based on the experimental data, the Analytic Hierarchy Process (AHP), an MCDM method, is used to find optimal machinability condition for rough and finish turning. The AHP results show that for rough turning, the optimal alternative would be with cutting velocity of 237mm/min, feed of 0.16mm/rev, depth of cut of 2mm under wet environment-friendly environment (2:13 rice bran oil and water+ 85g Matic surf in 4 litre). For finish turning, the optimal alternative corresponds to a cutting velocity of 140 mm/min, feed of 0.08 mm/rev, depth of cut of 2 mm under the same wet environment. These conditions may be recommended for use in industry.