Investigation of Drilling Rate and Overcut for Micro-EDM Drilling of Ti-Alloy Using Response Surface Methodology

The present study aims to investigate the micro electric discharge machining (micro-EDM) process for drilling on Ti-grade 2 alloy using the WC tool electrode. Experimental factors such as tool rotation, voltage, and capacitance are varied to assess their impact on machining outcomes; drilling rate and overcut. The experimental trials are conducted by using the Box-Behnken design (BBD)-based response surface methodology approach. Analysis of Variance (ANOVA) demonstrates that all machining parameters; voltage, tool rotation and capacitance are the significant variables affecting the response measures with a confidence level of 95%. Based on RSM, response equations have been generated between the experimental parameters and response outcomes. Moreover, numerical RSM-based desirability is applied to optimise both the drilling rate and overcut simultaneously. The optimum parameter setting proposed by this technique is 164.751 V of voltage and 10,000 pF of capacitance with no tool rotation. The performance outcomes at the optimal parameter show improvement of 1.35% and 4.48% for drilling rate and overcut, respectively.