Performance of Near Dry Hard Machining Through Pressurised Air Water Mixture Spray Impingement Cooling Environment

Abstract

The present paper emphasizes on experimental investigation, mathematical modelling, optimisation, tool life and cost analysis during machining of AISI D2 (heat treated) (55±1 HRC) steel using uncoated carbide tool through a novel method under spray impingement cooling environment. Taguchi based L16 orthogonal array was utilised to conduct the experiments. Analysis of variance with 95% confidence level shows that the feed and depth of cut, are the most compelling factor towards surface roughness as well as chip reduction coefficient whereas cutting speed is the utmost compelling feature associated to flank wear as well as chip-tool interface temperature. Optimised result is identified as v1-f1-d1 (machining speed of 63 m/min; cutting feed of 0.04 mm/rev and depth of cut of 0.1 mm) based on grey relational analysis and tool life is found to be 15 minutes at optimised cutting conditions. Flank wear due to abrasion, catastrophic failure due to diffusion, chipping and notch wear are noticed as the major tool wear mechanisms in hard turning. Mathematical machinability models show statistically significance because due to the superior coefficient of correlations. As the global machining cost for each part is less, uncoated carbide tools can machine effectively, efficiently and economically at optimum cutting conditions under spray environment.