: Optimization of Process Parameters for Machining of Al - 6061 - T6 Using Sinked EDM

Abstract

Materials used for aerospace application should have high strength to density ratio. Al-6061 T6 qualifies this requirement. It has good corrosion resistance and machinability. Moreover very high precision, accuracy and complex shapes are the features expected from microwave and optomechanical components used in aerospace. Complex components are not feasible for fabrication using conventional machining processes due to tool inaccessibiliity. EDM process caters need for such parts. In EDM, different parameters affect the material removal rate and surface finish of the components. So optimization of different parameters is necessary to achieve required accuracy and surface finish and minimize machining time. In this project, the effect of EDM parameters like pulse on time(Ton), pulse off time(Toff), voltage(V) and current(I) on material removal rate(MRR), electrode wear ratio(EWR) and surface roughness(SR) in Al-6061 T6 have been studied. The experiments are carried out as per taguchi design of experiment using L16 orthogonal array. The results were analyzed using analysis of variance(ANOVA) and response graphs. Signal to noise ratio(S/N) and analysis of variance (ANOVA) is used to analyze the effect of each parameters on MRR,EWR and SR. Current(I) is found to be most influential parameter for all the responses. Maximum MRR(36.7 mm3/min), minimum EWR(0.3%) and minimum SR(1.8 µm) could be achieved with respective combinations of process parameters. Grey analysis has been performed to find out parameters for optimum MRR, EWR and SR. A program has been developed to identify the input parameters corresponding to required SR.