Evaluation and multi-objective optimization of nose wear, surface roughness and cutting forces using grey relation analysis (GRA)

Abstract

Dual-phase structure with 1:1 ratio of austenite and ferrite is termed as “Duplex”. Lower cost of duplex stainless steel (DSS) with a combination of good strength and corrosion resistance in a critical environment is captivating many applications. This research work highlights the experimental study of effect of cutting parameters such as cutting speed, feed rate, AlTiN and AlTiCrN-coated tools on response parameters, viz. tool life, surface roughness and cutting forces. Multi-objective optimization using grey relation analysis (GRA) was done to optimize quality response characteristics. High-power impulse magnetron sputtering was used to deposit AlTiN and AlTiCrN coatings on tungsten carbide substrate. Performance measures such as tool life, surface roughness and cutting forces were measured during dry turning of DSS2205 and optimized using Taguchi’s GRA technique. AlTiCrN-coated tools exhibited the best results followed by AlTiN-coated tools and uncoated tools. Tool life achieved with AlTiCrN-coated tools is 7 times more than uncoated tools, in which surface roughness was found to be reduced by 67% and cutting forces by 25%. Weighted GRG grade shows that for all the tools used, a cutting speed of 100 m/min and feed rate of 0.12 mm/rev provided optimum results for response parameters. For change in weightage to response characteristics, different optimum conditions were found for all the tools used. AlTiCrN-coated tool with 100 m/min cutting speed and 0.12 mm/rev feed rate performed better with the highest tool life, the least surface roughness and cutting forces. The results were confirmed by S/N ratio plots.