Investigation on tool wear rate of brass tool during machining of Monel 400 alloy using electric discharge machine

Abstract

Electrical discharge machining (EDM) is a manufacturing process in which electrical discharges are used to bring about a desired shape of a workpiece. In this research work, the Tool Wear Rate (TWR) is studied by optimizing the EDM process parameters such as pulse on time, pulse off time, gap voltage and current. The main purpose of this work is to achieve minimum tool wear rate. Tool wear is measured by weight losses of the electrode to capture the extent of wear. In this paper, an investigation has been made on wear rate of brass tool during machining of Monel 400 alloy using electric discharge machining process. Central Composite Design (CCD) approach with five-level, four factorials has been employed to conduct this experiment. A mathematical model was developed using Response Surface Methodology (RSM) technique with Design expert software. Analysis of Variance (ANOVA) was done to find out the effects of pulse on time, pulse off time, Gap voltage and Current on tool wear. The analysis revealed that the increase in peak current slowly increases the tool wear while increase in pulse off time reduces tool wear. The minimum tool wear rate obtained was 0.0115 mm3/min for the process parameter combination of pulse on time 400 μs, pulse off time 250 μs, gap voltage 55 V and current 6A.