MSEC2007-31060 SOME INVESITIGATIONS INTO MULTI-OBJECTIVE OPTIMIZATION OF WIRE ELECTRO- DISCHARGE MACHINING OF AL/SIC P COMPOSITES

ABSTRACT Non-traditional process like wire electro-discharge machining (WEDM) is found to show a promise for machining metal matrix composites (MMCs). However, the machining information for the difficult-to-machine particle-reinforced material is inadequate. This paper is focused on experimental investigation to examine the effect of electrical as well as nonelectrical machining parameters on performance in wire electro-discharge machining of metal matrix composites (Al/SiC p ). Taguchi orthogonal arrays were employed to study the effects of combinations of voltage, current, pulse on-time, off-time, and wire speed and wire tension on kerf width and cutting speed. Voltage, current, and on-time were found to have significant effect on cutting speed and kerf width. The optimum machining parameter combinations were obtained for cutting speed and kerf width separately. Further, multi-objective optimization was done using Taguchi-Grey relational analysis. The process has been improved with the aid of Grey relational analysis and Taguchi orthogonal array. The results have been verified with confirmation experiments. INTRODUCTION In the drive for high performance materials for aerospace applications, metal matrix composites have been investigated by both industry and academia since the 1970s. These materials do not need any introduction today. Over the last three decades metal matrix composites (MMCs) have received attention all over the world because of their attractive properties, relative ease in fabrication technology and their potential to be availabl