Optimization of Machine Process Parameters in EDM for EN 31 Using Evolutionary Optimization Techniques

Nadeem Faisal,Kaushik Kumar

doi:10.3390/technologies6020054

Nadeem Faisal, Kaushik Kumar

Open Access

https://doi.org/10.3390/technologies6020054

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Journal: Technologies	Publication Date: Jun 5, 2018
Citations: 46	License type: CC BY 4.0

Affiliation: Birla Institute of Technology, Mesra

Abstract

Electrical discharge machining (EDM) is a non-conventional machining process that is used for machining of hard-to-machine materials, components in which length to diameter ratio is very high or products with a very complicated shape. The process is commonly used in automobile, chemical, aerospace, biomedical, and tool and die industries. It is very important to select optimum values of input process parameters to maximize the machining performance. In this paper, an attempt has been made to carry out multi-objective optimization of the material removal rate (MRR) and roughness parameter (Ra) for the EDM process of EN31 on a CNC EDM machine using copper electrode through evolutionary optimization techniques like particle swarm optimization (PSO) technique and biogeography based optimization (BBO) technique. The input parameter considered for the optimization are Pulse Current (A), Pulse on time (µs), Pulse off time (µs), and Gap Voltage (V). PSO and BBO techniques were used to obtain maximum MRR and minimize the Ra. It was found that MRR and SR increased linearly when discharge current was in mid-range however non-linear increment of MRR and Ra was found when current was too small or too large. Scanning Electron Microscope (SEM) images also indicated a decreased Ra. In addition, obtained optimized values were validated for testing the significance of the PSO and BBO technique and a very small error value of MRR and Ra was found. BBO outperformed PSO in every aspect like computational time, less percentage error, and better optimized values.

Highlights

The definition of the word “machining” has evolved significantly over the last couple of decades.In a broader term, machining can be defined as the process to remove material from a work piece or a process where a piece of material is given desired shape and size through a controlled material removal process
It was found that material removal rate (MRR) and SR increased linearly when discharge current was in mid-range non-linear increment of MRR and roughness parameter (Ra) was found when current was too small or too large
Owing to advantages offered by the non-traditional machining processes, these are available for an extensive range of industrial applications

Summary

Introduction

In a broader term, machining can be defined as the process to remove material from a work piece or a process where a piece of material is given desired shape and size through a controlled material removal process. The traditional processes such as milling, turning, grinding, drilling, etc., to remove material through mechanical abrasion, micro chipping, or chip formation. The above disadvantages have led to the development of other material removal mechanisms like mechanical, chemical, thermal, electrochemical, and different hybrid mechanism These material removal mechanisms have resulted in machining processes referred to as non-traditional machining processes. The source of energy used differ from process to process and can be categorised : thermal & electro-thermal

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