Assessing the Effects of Uncoated and Coated Electrode on Response Variables in Electrical Discharge Machining for Ti-6Al-4V Titanium Alloy

The coated electrodes with high heat resistant alloy materials can considerably improve the efficiency of electrical discharge machining (EDM) process. In the present study, the influence of Aluminum Chromium Nickel Coated aluminium electrode was investigated on the quality criteria using EDM while machining Titanium alloy (Ti - 6Al-4V). The peak current, gap voltage and pulse-on time were used as input parameters to analyze the material removal rate, tool wear rate and surface roughness under the L16 based Taguchi method and ANOVA method. It was observed that Aluminum Chromium Nickel (AlCrNi) coated electrode could produce higher material removal rate (MRR), lower of tool wear rate (TWR) and surface roughness (Ra) than uncoated electrode. Compared with EDM with uncoated electrodes, the quality indicators in EDM with coated electrode are better, namely 8% higher MRR, the lower TWR and Ra are 8% and 24%, respectively. The better surface finish was also observed with the coated electrode due to its thermal conductivity.