Experimental Investigation and Analysis of Process Robustness in Electric Discharge Machining of Titanium Alloy (TI-6AL-4V)

The aim of this work is to investigate the influence of process parameters and determine the optimum process parameters in electric discharge machining (EDM) of titanium alloy (Ti-6AI-4V). The parameters considered are peak current, pulse-on-time and pulse-off-time where as the responses are Material Removal Rate (MRR) and Surface Roughness(SR). MITSUBISHI EA8 spark erosion machine is employed for this study and copper tungsten electrode of ∅14 mm is used in experimental trials. The experimental trials are conducted based on Taguchi L27 orthogonal array with three levels of each machining parameters. The signal-to-noise ratio, the analysis of variance (ANOVA), and regression analysis are employed to find the optimal levels and to analyze the effects of machining parameters on Metal removal rate and Surface roughness. Confirmation tests with the optimal levels of machining parameters are carried out in order to illustrate the effectiveness of Taguchi optimization method. The validity of Taguchi's approach to process optimization is well established.