Optimisation of Cutting Tool Geometry and Operating Parameters based on Taguchi Method for Turning AISI D2: Surface Roughness Analysis

This paper presents an experimental study on optimising surface roughness in CNC turning of AISI D2 tool steel under wet conditions, using conventional and wiper carbide inserts. Taguchi’s L 16 orthogonal array and ANOVA analysis are used to investigate the impact of spindle speed, feed rate, depth of cut, and tool geometry on surface roughness (Ra). The study concludes that the wiper insert yields significantly better surface quality, with tool type contributing 32.85% to surface roughness variation-more than any other parameter. The study also shows that there are no noticeable mutual interactions among the parameters investigated, except between feed rate and tool type or geometry with PCRs of 26.82%. Confirmation tests support the Taguchi-derived optimum configuration. The work aims to inform practical choices in cuting tool and parameter selection for hard turning operations.