Investigation of tool wear, surface roughness, sound intensity and power consumption during hard turning of AISI 4140 using multilayer-coated carbide inserts

Abstract

The present study investigated the machinability aspects namely, surface roughness, sound intensity, power consumption and crater wear during dry turning of hardened AISI 4140 steel (63 HRC) employing (TiCN/Al₂O₃/TiN) multilayer-coated carbide inserts. Three machining parameters (feed, depth of cut and cutting speed) were used to investigate the impacts of these parameters on output variables. The relationship between machining parameters and output parameters was determined using response surface methodology. The analysis of variance was employed to evaluate the contributions of input parameters on workpiece and tool. The main effect plots illustrated the effects of cutting speed, feed and depth of cut on surface roughness, power consumption and sound intensity. The second order regression models were developed with 97.49% adequacy to predict the tool wear. Results show that the feed was the most dominant factor that affects surface roughness. Increasing the feed value increase the surface roughness, power consumption and sound intensity. In the other part of this study, the constant values for feed (0.3 mm/rev), depth of cut (0.7 mm) and cutting speed (150 m/min) have been selected to evaluate a tool life that has 0.3 mm crater wear criterion. The results indicated that multilayer-coated carbide inserts presented very good tool life and reached to 0.3 mm in 90 min. The experimental study results showed that chipping and abrasion were found to be the significant wear mechanism during hard turning of AISI 4140 steel. The cutting speed was the most significant parameters on the tool wear. Although, high cutting speed results in the good surface finish but adversely increases the tool crater wear.