Optimal Selection of Process Parameters in CNC End Milling of Al 7075-T6 Aluminium Alloy Using a Taguchi-fuzzy Approach

Abstract This paper describes the application of the fuzzy logic integrated with Taguchi method for minimizing the surface roughness and maximizing the material removal rate simultaneously, in CNC end milling of Al 7075 T6 aerospace aluminium alloy. The input parameters taken into consideration are speed, feed, depth of cut and nose radius. Al 7075 T6 is one of the highest strength aluminium alloys in 7000 series family. In Taguchi method, L 27 orthogonal array with 4 factors and 3 levels are chosen and S/N ratios are calculated. The S/N ratios of roughness and material removal rate are fed as inputs to fuzzy logic system and output received is Multi response performance index (MRPI). With application of ANOVA, the nose radius and depth of cut are identified as the most significant parameters contributing about 31% of the variance. Further a confirmation test showed that, there was a significant improvement in MRPI of optimal process parameters as compared to MRPI of initial process parameters.