Performance Appraisal of Cryogenically Treated Tool in Dry, MQL and Cryogenic Machining of Inconel 718

Abstract

Inconel 718 is widely used nickel-based alloy in engineering applications because of its favorable mechanical properties. Though, machining of this alloy is difficult and results in poor tool wear and surface quality. Selection of suitable machining condition is essential for improving the machining performance of this expensive and hard to cut the material. The study compares the use of cryogenically treated inserts in dry, MQL and cryogenic environment. Cutting speed, feed rate and depth of cut are considered as control parameters, whereas surface roughness and tool flank wear are the response parameters. The adequacy of developed response surface models (RSM) is tested on the basis of the correlation coefficient (R2). Later, the effect of cutting parameters on surface quality and tool wear is presented for all three machining conditions. Application of liquid nitrogen with cryogenically treated inserts besides the use of MQL gives the least tool vibration, the lower cutting temperature during experimentation. Later on, the good surface quality of workpiece along with least tool wear is noticed. The performance curves show that the use of cryogenically treated insert along with MQL and liquid nitrogen is found to be better than other conditions. This is accepted as the best way for enhancing the machinability of Inconel 718.