Material Characterization of Titanium Alloy and Optimization of Process Parameters for Electrical Discharge Machining

Abstract

Titanium alloys are used extensively in aerospace applications such as components in aero-engines and space shuttles, Electric discharge machining (EDM) is one of the leading edge machining processes successfully used to machine hard-to-cut materials in a wide range of industrial applications, primarily due to its superior strength-to-weight ratio. The operating parameters of the machine need to be optimized to enhance EDM performance. The present work deals with the optimization of process parameters through electrical discharge machining by machining titanium alloy. Titanium alloy specimens are prepared using the mould casting method. The specimens are then machined for tests to be performed according to the dimensions of the ASTM standards. The specimens will then be tested according to the ASTM standard specifications for Tensile Test on Universal Testing Machine, Impact Test on Charpy Impact Test Machine and hardness test on Vicker's hardness testing machine. On EDM, machining-drilling is carried out by selecting the input parameters such as electrode materials, diameter of the electrode and voltage. These three input parameters, electrode materials-copper, aluminum and tungsten, electrode diameters-0.4 mm, 0.5 mm and 0.6 mm, voltage-4 volts, 6 volts and 8 volts, are selected at three levels. The output parameter is measured by an instrument named Metutoyo, such as surface roughness. SEM (Scanning Electron Microscope) analysis studies the microstructure of the drilled EDM hole. The optimum electrode selected is electrode made of tungsten after testing and machining, best results are obtained for 0.4 mm diameter drill hole and 8 volt voltage.

Keywords: Micro EDM drilling, DOE, TAGUCHI and ANOVA