ANALYSIS OF WEDM PARAMETERS IN MACHINING OF AL6061 COMPOSITE ALLOY USING DESIGN OF EXPERIMENTS

Abstract

Aluminium metal matrix composites are finding irreplaceable place in the aircraft and vehicle for its weight to strength ratio. The advent of new materials is really posing challenges on machinability characteristics especially in conventional machining. The metal matrix composites material during machining often experience the overcut, formation of sharp edges and excessive tool wear. To overcome the machining challenges, aluminium metal matrix composite (AMMC) i.e. Al6061 alloy reinforced with 6% wt of Al₂O₃ is machined using Wire Electric Discharge machine (WEDM). The chosen experimental design was implemented to investigate the impact of process parameters on the output parameters e.g. machining rate and surface roughness (R_a). The chosen process variables were varied up to five levels and central composite design (CCD) was adapted to Design of Experiments (DoE). To create a second order regression equation connecting response characteristics and process variables, response surface methodology (RSM) was applied. R² values of MR and R_a are found to be 90.36% and 91.05%, respectively. Based on ANOVA, the most influencing parameter that affects the MR is found to be peak current (B) which is at 74.20%. Moreover, the most influencing parameter that affects the R_a is found to be peak current (B) which is at 62.04%. The error percentage is notably low at 0.44% and 0.84% for MR and SR, respectively.