Electric Discharge Machining is mainly used for very hard materials. Now a days we know that product and process technology is very advance, many types of new materials are being developed which have very high strength, high thermal and electrical conductivity which are difficult to machine by traditional machining methods. So Non-conventional machining methods are used to machine such type of materials, EDM is also one of the Non-conventional machining methods which is used to machine such advance hard and brittle materials to satisfy the present days product needs like aerospace, mould, dies and other applications. Mixing of powders into dielectric fluid is a one of the recent advancement in the EDM process to improve its process capabilities and is known as Powder Mixed Electric Discharge Machining (PMEDM) process.
The objective of this work is mainly to study the effect of various input parameters like pulse-on-time, discharge current, tool material and grit size on the various output parameters like MRR, TWR, Surface Roughness, Hole Diameter Variation and Micro structure. In this study, these output parameters are studied by using the ANOVA through Minitab17 software. By using this software, study the Means and S/N ratios for all these parameters. Optimization of the whole process through Grey Relational Analysis for obtains the better output response simultaneously. Improvement in output responses by using grey relational analysis are 64.84% in TWR, 52% in HDV, 49.78% in MRR and 41.57% in SR. Micro structure has been also observed through SEM analysis.
Table of Contents
CHAPTER 1: INTRODUCTION
1.1 Introduction
1.2 History of EDM
1.3 Working Principle of EDM
1.4 Process variables
1.5 Performance Measures
1.6 Categories of EDM
1.6.1 Die-sinking EDM
1.6.2 Wire EDM
1.7 Powder mixed EDM
1.8 Advantages of EDM
1.9 Dis-advantages of EDM
1.10 Applications of EDM
CHAPTER 2: LITERATURE REVIEW
2.1 Influence of powder characteristics
2.2 Gap in Literature Survey
2.3 Problem Formulation
2.4 Objectives for Research Work
2.5 Methodology Flow Chart
CHAPTER 3: EXPERIMENTAL DETAILS
3.1 Experimental set-up of EDM
3.2 Selection of materials
3.2.1 Work-piece material
3.2.2 Tool material
3.2.3 Powder material
3.3 Process parameters
3.4 Design of experiments using Taguchi
3.5 Performance Measures
3.5.1 Material removal rate (MRR)
3.5.2 Tool wear rate (TWR)
3.5.3 Surface roughness (SR)
3.5.4 Hole Diameter Variation(HDV)
3.5.5 Scanning electron microscope (SEM)
3.6 Work-piece after machining and testing
CHAPTER 4: OPTIMIZATION OF OUTPUT PARAMETERS
4.1 Introduction
4.2 Experimental results of MRR, TWR, SR and HDV
4.3 S/N Ratios of MRR, TWR, SR and HDV
4.4 Optimization of material removal rate
4.4.1 Results for S/N Ratios of MRR
4.4.2 Results for mean of MRR
4.5 Optimization of tool wear rate
4.5.1 Results for S/N Ratios of TWR
4.5.2 Results for mean of TWR
4.6 Optimization of surface roughness
4.6.1 Results for S/N Ratios of SR
4.6.2 Results for mean of SR
4.7 Optimization of hole diameter variation
4.7.1 Results for S/N ratios of HDV
4.7.2 Results for mean of HDV
4.8 Calculation of optimal design for output responses
4.8.1 Optimal design for MRR
4.8.2 Optimal design for TWR
4.8.3 Optimal design for SR
4.8.4 Optimal design for HDV
CHAPTER 5: GREY RELATIONAL ANALYSIS
5.1 Introduction
5.2 Experimental Data for MRR, TWR, SR and HDV
5.3 Grey Relational Analysis
5.3.1 Normalize the Original Sequence and Deviation Sequence
5.3.2 Grey Relational Coefficient and Grey Relational Grade
CHAPTER 6: SCANNING ELECTRON MICROSCOPE (SEM)
6.1 Introduction
CHAPTER 7: CONCLUSION AND FUTURE SCOPE
7.1 Conclusion
7.1.1 Material Removal Rate (MRR)
7.1.2 Tool Wear Rate (TWR)
7.1.3 Surface Roughness (SR)
7.1.4 Hole Diameter Variation(HDV)
7.1.5 Grey Relational Analysis (GRA)
7.2 Future Scope
Research Objectives and Focus Areas
The primary research objective of this work is to evaluate the feasibility of machining High Carbon High Chromium Alloy Steel (D2 Steel) using Powder Mixed Electric Discharge Machining (PMEDM). The study investigates the impact of various input parameters—such as discharge current, pulse-on time, tool material, and powder grit size—on key performance measures including Material Removal Rate (MRR), Tool Wear Rate (TWR), Surface Roughness (SR), and Hole Diameter Variation (HDV) to determine optimal machining settings.
- Optimization of PMEDM process parameters using the Taguchi method to achieve superior surface integrity and machining efficiency.
- Comprehensive analysis of the effect of tool material variations (Copper vs. Copper-Chrome) on output quality.
- Implementation of Grey Relational Analysis to facilitate multi-response optimization for simultaneous improvement of conflicting performance metrics.
- Microstructural examination of machined surfaces using Scanning Electron Microscopy (SEM) to assess cracks, surface voids, and recast layer characteristics.
Excerpt from the Book
1.1 INTRODUCTION
The growing trend to use slim, light and compact mechanical components in automobile, aerospace, medical, missile, and nuclear reactor industries has led to the development of high strength, temperature resistant, and hard materials during last few decades. It is almost impossible to find sufficiently strong and hard tools to machine aforesaid materials at economic cutting speeds [1]. Moreover, machining of complex shapes in these materials with low tolerances and high surface finish by conventional methods is even more troublesome. Hence, there is great demand for new machining technologies to cut these ‘difficult-to-machine’ materials with ease and precision. Among modern machining processes, electric discharge machining (EDM) has become highly popular in manufacturing industries due to its capability to machine any electrically conductive material into desired shape with required dimensional accuracy irrespective of its mechanical strength [4].
Summary of Chapters
CHAPTER 1: INTRODUCTION: This chapter provides an overview of the growing demand for modern machining technologies for hard materials, details the historical development of EDM, and describes the fundamental working principles and common process variants.
CHAPTER 2: LITERATURE REVIEW: This section summarizes existing research on PMEDM, explores the influence of various powder characteristics on machining performance, and identifies critical gaps in current literature regarding the machining of D2 steel.
CHAPTER 3: EXPERIMENTAL DETAILS: This chapter outlines the experimental setup, selection of materials including the D2 steel workpiece and SiC powder additives, and defines the methodologies used for measuring MRR, TWR, SR, HDV, and SEM analysis.
CHAPTER 4: OPTIMIZATION OF OUTPUT PARAMETERS: This section details the application of the Taguchi method to analyze and optimize individual output parameters, presenting the analysis of variance (ANOVA) and main effects plots for each response measure.
CHAPTER 5: GREY RELATIONAL ANALYSIS: This chapter utilizes Grey Relational Analysis to solve the multi-response optimization problem, determining the optimal combination of machining parameters that provide the best overall performance.
CHAPTER 6: SCANNING ELECTRON MICROSCOPE (SEM): This chapter presents the microstructural analysis of machined samples, documenting the impact of different parameter settings on surface topography, micro-cracks, and recast layer formation.
CHAPTER 7: CONCLUSION AND FUTURE SCOPE: This final chapter synthesizes the experimental findings, highlights the achieved improvements in machining outputs, and suggests directions for future research in the field.
Keywords
Electric Discharge Machining, EDM, PMEDM, D2 Steel, Taguchi Method, Material Removal Rate, MRR, Tool Wear Rate, TWR, Surface Roughness, Hole Diameter Variation, Grey Relational Analysis, Scanning Electron Microscope, Process Optimization, Surface Integrity.
Frequently Asked Questions
What is the primary focus of this research?
The research focuses on the optimization of process parameters for Powder Mixed Electric Discharge Machining (PMEDM) specifically applied to High Carbon High Chromium Alloy Steel (D2 Steel).
What are the main performance measures evaluated in this study?
The study evaluates four key performance measures: Material Removal Rate (MRR), Tool Wear Rate (TWR), Surface Roughness (SR), and Hole Diameter Variation (HDV).
What is the primary goal of the experimental methodology?
The goal is to determine the most effective combination of machining parameters—discharge current, pulse-on time, tool material, and powder grit size—to simultaneously optimize conflicting output metrics.
Which statistical method is used to optimize the process?
The researchers utilize the Taguchi design of experiments technique to manage the experimental trials and Grey Relational Analysis (GRA) for multi-objective optimization.
What does the main body of the work cover?
The main body covers the literature review, detailed experimental procedures, parameter optimization via Taguchi/GRA, and microstructural analysis using SEM.
Which key terms best describe this work?
Key terms include EDM, PMEDM, D2 Steel, Taguchi Method, Surface Integrity, and Grey Relational Analysis.
How does the addition of powder to the dielectric fluid affect the EDM process?
The addition of powder particles, such as Silicon Carbide, enlarges the discharge gap and widens the discharge passage, which improves machining stability and results in superior surface finish and higher material removal rates compared to conventional EDM.
What role does Grey Relational Analysis play in the study?
It allows for the conversion of multi-performance characteristics into a single performance index, facilitating the optimization of the process when different outputs like MRR and surface roughness need to be balanced.
What does the SEM analysis reveal about the machined D2 steel?
SEM images are used to identify surface features such as micro-cracks, surface voids, white compounds (recast layers), and the thickness of the over-layer, which are critical for assessing surface integrity.
- Quote paper
- Kanwal Singh (Author), Dharamjit Singh (Author), 2017, Optimization of Process Parameters of Powder Mixed Electric Discharge machining for D2 Steel, Munich, GRIN Verlag, https://www.grin.com/document/385408
