Drilling of Micro-holes in Titanium Using Micro-EDM: A Parametric Investigation

Abstract

The present paper aims to perform experimental investigation of drilling micro-holes in titanium alloy using micro-electrical discharge machining (µEDM) process. Process parameters such as voltage, feed rate, and tool rotation speed are varied during experimentation to evaluate their effect on response measures such as machining time (MT), overcut at entry (OC (en)), and overcut at exit (OC (ex)). Taguchi L9 orthogonal array is utilized to conduct the experiments. Analysis of variance (ANOVA) is employed to find the contribution of process parameters for each response measure. Empirical models for MT, OC (en), and OC (ex) as functions of voltage, feed rate, and tool rotation speed are developed by regression analysis, wherein average error is found ≤4.2% between experimental and predicted values. Furthermore, desirability approach is also employed for multi-response optimization, wherein confirmation test result shows ≤3.39% error with the predicted optimum value.