Effect of process variables on titanium alloy TI-6AL-4V EDM parameters with graphite electrodes

Electrical discharge machining has developed into a prominent method for machining hard and tough materials using electrochemical energy. In this investigation, Titanium Alloy Ti-6Al-4V was machined utilizing graphite electrodes through the EDM process. Key specifications for machining, such as discharge current, pulse on-time, and pulse off-time, were carefully optimized to achieve superior machining characteristics. The fundamental composite design of the methodology of response surface (RSM) served as the foundation for the experimental design. Surface roughness (SR) and material removal rate (MRR) were the two aspects of machining that were examined. ANOVA was used to determine which factors were most important in influencing MRR and SR. Discharge current was determined as the most important machining parameter, followed by pulse on-time and pulse off-time. It was found that, independent of pulse off-time, MRR and SR rose with greater discharge current and pulse on-time. The increased current and extended pulse on-time generated higher ionization temperatures, leading to increased material removal. However, this also caused more pronounced surface irregularities and increased surface hardness due to the formation of craters and voids, which resulted in a higher SR.