Investigation of the machining parameters and integrity of the work and wire surfaces after finish cut WEDM of commercially pure titanium

This paper investigates the finish cutting operation of wire electrical discharge machining for commercially pure titanium. The effects of key process parameters such as wire type (zinc coated and uncoated brass wire), pulse on time (TON), pulse off time (TOFF), peak current (IP), wire feed (WF), servo voltage (SV) and wire offset (WOFF) were investigated, on machining characteristics (cutting speed, surface roughness) and the surface integrity after finish cut operation. It was confirmed from investigation that lower value of pulse energy parameters and WOFF, in conjunction with uncoated brass wire as a tool improves the surface finish in trim cut. The results of ANOVA elaborate that type of wire material, TON and wire offset are very influential parameters for cutting speed and surface roughness during trim cut process. The scanning electron microscopy reveals that a smoother surface can be obtained while machining with lower TON, IP and wire offset coupled with uncoated brass wire. Energy dispersive x-ray indicates higher concentration of oxygen content on trim cut machined surface rather than rough cut. The x-ray diffraction investigation reported that peak intensity gets lowered down due to increase of pulse discharge energy in trim cut stage of WEDM. Further, the fuzzy logic methodology is used to establish the optimal parametric combination for multiple responses characteristics using MATLAB7.8.0 (Release2009a) and MiniTab 15software.