Performance of Copper Electrode for Machining En-19 and Nickel Plated En-19 Alloy Steel by EDM

Mukesh Regmi

doi:10.11648/j.ijimse.20170201.11

Abstract

Electric discharge machining (EDM) is non-conventional machining processes that involves a transient spark discharges through the fluid due to the potential difference between the electrode and the work piece. The aim of this project is to determine the proper machining conditions for machining EN-19 and Nickel Plated EN-19 work pieces using electrical discharge machining (EDM). Basically, improper choice of parameter in EDM machine may result a few problems like the machine may cause of poor machining performance and it will decrease the accuracy of the products and incurs a lot of cost. The aim of this project is to determine the optimal machining parameters for machining work pieces using electrical discharge machining (EDM). Intensity of current, pulse on time and pulse of time were used as process parameters. This paper explores the characteristic of electric discharge machine (EDM) that is tool wear rate (TWR) and material removal rate (MRR) by using different workpiece materials namely En-19 and Nickel Plated En-19 alloy steel and copper as a tool material in order to increase the understanding of EDM processes. To achieve this project objective, an experimentation was done where the approach used was response surface methodology in which a well-designed experimental scheme named box behnken design was used to reduce the total number of experiments into 15 for each workpiece material. A second order empirical model is developed to predict the MRR and TWR. Finally ANOVA analysis is done to validate the model developed.

Highlights

Rapid technological advancements in the area of new materials and alloys with ever-increasing properties like strength, hardness, heat resistance, toughness and wear resistance have created many obstacles during machining of these materials by conventional machining process
Response surface methodology (RSM) is used which is a collection of mathematical and statistical techniques that are useful for modeling and analysis of problems in which output or response is influenced by several variables
The main effect of current is significant. It shall not be interpreted as pulse off-time and pulse off time do not have any effect on the material removal rate (MRR)

Summary

Introduction

Rapid technological advancements in the area of new materials and alloys with ever-increasing properties like strength, hardness, heat resistance, toughness and wear resistance have created many obstacles during machining of these materials by conventional machining process. Another choice of machining these materials has been into use known as non- conventional machining. These nonconventional machining processes may come into the equation for many reasons, the main are machinability, work piece shape, complexity, surface integrity and precision requirement. Due to a high temperature of the sparks, work material is melted and vaporized, but the electrode material is melted and vaporized, which is known as tool wear [2]

Methods

Results

Conclusion