Machinability characteristics analysis of hard turning operation on AISI 4340 steel using physical vapor deposition multilayer coated carbide cutting tool in the dry environment

Abstract

AISI 4340 hardened steel is usually used in axle shafts, main shafts, gear, and couplings. Using multi-layer physical vapor deposition a coated tool, an attempt was made to optimize the input variables on precise turning on hardened AISI 4340 grade steel. The cutting speed, feed rate, and depth of the cut were the applied process factors in the dry-cutting environment. Furthermore, surface roughness (Ra), flank wear (VBc), cutting temperature (T), and chip morphology were considered as technological responses. The Taguchi L₂₇ standard orthogonal array with three levels and three factors was used in the experiment. Furthermore, scanning electron microscopy and energy dispersion spectroscopy were used to analyze tool wear and chip morphology characteristics. The relevance of the input process factors on the measured responses was determined using analysis of variance analysis. The feed rate was observed to have a dominant impact on the surface roughness in the trials. At an optimal parametric combination with 80 m/min cutting speed, 0.05 mm/rev feed rate, and 0.3 mm depth of cut obtained from the Taguchi-TOPSIS optimization method. The enhancement of the closeness coefficient was observed to be 0.2372. The generated second-order regression model was demonstrated to be of high significance. The strategy and outcomes of this research will help metal machining enterprises to augment manufacturing productivity when working with hardened steel.