Machinability Evaluation by Single Electrical Discharge

Abstract

Electrical discharge machining is widely used in processing complex shaped parts. The method uses a tool electrode having a specific geometry, but the tool wear can affect such geometry in time. An affordable material for obtaining tool electrodes with complicated profiles can be electrolytic copper. Some issues appear when workpiece materials made also out of copper or copper alloys are processed, as the copper tool life span decreases. Machinability is the property of a material that indicates good process outcomes for the manufacturer, such as a high material removal rate and low tool wear. In order to determine some machinability indicators such as tool wear and material removal rate, a set of experiments were designed for single discharge machining using thin sheets of copper as tool electrodes and thin sheets of brass as test pieces, with workpiece thicknesses of 0.1 mm. The craters obtained after discharge were analyzed by means of a digital microscope. Based on these results, a statistical analysis was developed and the influence of input process factors was evaluated.