ABSTRACT
Ti-6Al-4V, an advanced engineering material is difficult-to-machine using conventional machining process due to its high strength. It has properties like low weight ratio, outstanding corrosion resistance along with high level of reliable performance in micro components. Micro-electro-discharge machining (Micro-EDM), a popular nontraditional machining process has been identified as the most appropriate machining process for such material. In this paper, the effect of various conducting powders such as copper, nickel and cobalt with different concentrations are mixed with deionized water dielectric, on various responses such as material removal rate (MRR), tool wear rate (TWR), overcut (OC) and taper has been presented. Also, principal component analysis (PCA) has been applied to select the optimal parametric combination of micro-EDM process to achieve optimal values of MRR, TWR, OC and taper during micro-through hole machining. The optimal process parametric setting obtained from the proposed approach is peak current (Ip) of 1.5 A and cobalt (Co) powder concentration of 4 g/L so as to obtain the desired responses. It is also observed from the SEM image that the machined profile and surface topography obtained through the multi-objective optimal parametric combination based on PCA is quite satisfactory and can be applied to achieve geometrically more accurate micro-through holes on Ti-6Al-4V.