In the present study, the effect of aluminium tool electrode has been studied on stainless steel 316 and AISI D2 steel. Dielectric used for the study was EDM oil. Experiments were conducted based on L9 orthogonal array. The experimental study on the effect of input parameters i.e. current, pulse on time and pulse off time on output parameters material removal rate (MRR), tool wear rate (TWR) and surface roughness (SR). The workpiece materials selected were AISI D2 steel and SS 316. The tool electrode used was Aluminium and EDM oil as dielectric fluid. Taguchi design of experiments was used to design experiments, L9 orthogonal array was applied using MINITAB software. Signal to noise ratio and ANOVA were employed for parameter optimization and to achieve max MRR, min TWR and SR. The results indicate that the most influencing factor for MRR is Pulse off time. For TWR, the most influencing factor is current. For SR, the most influencing factor is pulse on time.
Table of Contents
1. Introduction
1.1 Introduction and History of EDM
1.2 Working Principle
1.3 EDM Process
1.4 Advantages of EDM
1.5 Disadvantages of EDM
1.6 Dielectric Fluid
1.7 Electrode Material Selection
1.7.1 Electrical Conductivity
1.7.2 Melting Point
1.7.3 Structural Integrity
1.7.4 Mechanical Properties
1.7.5 Low Wear Rate
1.7.6 Metallic Electrodes
1.8 EDM Parameters
1.8.1 Pulse On Time
1.8.2 Pulse Off Time
1.8.3 Peak Current
1.8.4 Voltage
2. Literature Review
2.1 Introduction
2.2 Literature Survey
2.3 Gap in Literature
2.4 Objective of Present Study
3. Methodology
3.1 Phasing of Work
3.2 Experimental Setup
3.3 Workpiece and Electrode used for experimental work
3.3.1 Workpiece Material
3.3.2 Electrode Material
3.4 Machine used for experiments
3.5 Specifications of EDM
3.6 Machine used to measure weight
3.7 Machine used to measure surface roughness
3.8 Taguchi Method
3.8.1 Input Parameters
3.8.2 Response Variables
3.9 Evaluation of MRR
3.10 Evaluation of EWR
4. Analysis and Results
4.1 Analysis and results of MRR of AISI D2 steel
4.1.1 Analysis and results of MRR for machined surface
4.1.2 Observation table for MRR
4.1.3 Analysis of Variance for MRR
4.1.4 Confirmation Test
4.1.5 Main effect plots
4.2 Analysis and result of TWR of AISI D2 steel
4.2.1 Results and analysis of TWR for machined surface
4.2.2 Observation Table for TWR
4.2.3 Analysis of Variance for TWR
4.2.4 Confirmation Test
4.2.5 Main effects plot
4.3 Analysis and results of SR of AISI D2 steel
4.3.1 Results and analysis of SR for machined surface
4.3.2 Observation Table for SR
4.3.3 Analysis of Variance
4.3.4 Confirmation Test
4.3.5 Main effects plot
4.4 Analysis and results of MRR of SS316
4.4.1 Analysis and results of MRR for machined surface
4.4.2 Observation table for MRR
4.4.3 Analysis of Variance for MRR
4.4.4 Confirmation Test
4.4.5 Main effect plots
4.5 Analysis and result of TWR of SS316
4.5.1 Results and analysis of TWR for machined surface
4.5.2 Observation Table for TWR
4.5.3 Analysis of Variance for TWR
4.5.4 Confirmation Test
4.5.5 Main effects plot
4.6 Analysis and results of SR of SS316 steel
4.6.1 Results and analysis of SR for machined surface
4.6.2 Observation Table for SR
4.6.3 Analysis of Variance
4.6.4 Confirmation Test
4.6.5 Main effects plot
5. Conclusion and Scope for future work
6. References
Research Objectives and Focus
This dissertation aims to investigate the influence of key input parameters—specifically peak current, pulse on time, and pulse off time—on the performance measures of Material Removal Rate (MRR), Tool Wear Rate (TWR), and Surface Roughness (SR) during the Electric Discharge Machining (EDM) of AISI D2 steel and SS 316, utilizing an aluminium electrode. The research employs the Taguchi method and L9 orthogonal arrays to optimize these parameters for enhanced machining productivity and quality.
- Experimental investigation of EDM characteristics using aluminium electrodes.
- Application of the Taguchi design of experiments to optimize input parameters.
- Statistical analysis of data using Signal-to-Noise (S/N) ratios and ANOVA.
- Comparison of machining performance on AISI D2 steel and SS 316.
Excerpt from the Book
1.1 Introduction and History of EDM:
When sparking takes place between two electrically conductive materials which are placed very close to each other, a small amount of material is removed from each of the material. It was first discovered by Joseph Priestly in 1770s. The Electric discharge machining started developing in mid 1970s. In mid 1980s, the EDM techniques were transferred to a machine tool. Today, it is the viable technique in the metal cutting industry with a wide number of applications and advantages.
The metal removal due to sparking was realized and attempts were made to harness and control the spark energy to employ it for useful purpose that is machining of metals. It was found that the spark of short duration and high frequency are needed for efficient machining. Further, it was also observed that if we submerge the discharge in dielectric, we can concentrate energy onto a small area.
A relaxation circuit that is RC circuit was proposed in which tool and workpiece i.e. electrodes are immersed into the dielectric like kerosene, and are connected to a capacitor. The capacitor is charged from a direct current source. Fig. 1.1 shows the RC circuit. As soon as the potential across the tool and the workpiece crosses the breakdown voltage, the sparking takes place at a point of least electrical resistance, which is usually the smallest inter-electrode gap (IEG). After every successive discharge capacitor recharges and spark will takes place at the next narrowest gap. Whenever a spark occurs heat is generated, which is shared in different modes by workpiece, tool, dielectric, debris and other parts of the system.
Summary of Chapters
Chapter 1- Introduction: Provides an overview of EDM history, working principles, process advantages, and the selection criteria for electrode materials and parameters.
Chapter 2- Literature Review: Summarizes previous research on EDM variables, identifying a research gap concerning the use of aluminium electrodes for machining SS 316 and AISI D2 steel.
Chapter 3- Methodology: Details the experimental design, including the Taguchi L9 orthogonal array, machine specifications, and the calculation procedures for MRR and EWR.
Chapter 4 Analysis and Results: Presents the statistical analysis of experimental data for MRR, TWR, and SR, utilizing S/N ratios and ANOVA to determine the most significant factors for both workpiece materials.
Chapter 5 – Conclusion and Scope for future work: Outlines the findings regarding the most influencing parameters for MRR, TWR, and SR, while suggesting future research directions such as using different dielectrics or powder-mixed EDM.
Keywords
Electric Discharge Machining, EDM, Material Removal Rate, MRR, Tool Wear Rate, TWR, Surface Roughness, SR, Taguchi Method, AISI D2 Steel, SS 316, Aluminium Electrode, Analysis of Variance, ANOVA, Dielectric Fluid.
Frequently Asked Questions
What is the core subject of this dissertation?
The dissertation focuses on the experimental study of Electric Discharge Machining (EDM) performance, specifically measuring Material Removal Rate, Tool Wear Rate, and Surface Roughness.
What are the primary themes addressed?
The study centers on the interaction between input parameters (current, pulse on time, pulse off time) and the machining performance of two hard-to-cut alloys: AISI D2 steel and SS 316.
What is the research goal?
The primary goal is to optimize EDM process parameters to maximize the Material Removal Rate while minimizing the Tool Wear Rate and Surface Roughness using an aluminium tool electrode.
Which scientific methodology is utilized?
The study utilizes the Taguchi method of design of experiments (L9 orthogonal array) and statistical tools like Signal-to-Noise (S/N) ratios and ANOVA for performance optimization.
What does the main body cover?
The main body covers the comprehensive experimental setup, data collection for both workpieces, and detailed ANOVA-based analysis of the results to identify the most significant controlling factors.
Which keywords define this research?
Key terms include EDM, Material Removal Rate (MRR), Tool Wear Rate (TWR), Surface Roughness (SR), Taguchi Method, and ANOVA.
Why was an aluminium electrode chosen for this study?
The study identifies that while aluminium is a good conductor and cost-effective, it remains under-researched for EDM applications, providing a gap for this investigation.
What conclusions were drawn for AISI D2 steel?
The results indicated varying significant factors for different output measures, with pulse off time being particularly influential for MRR in the tested configurations.
How does the performance for SS 316 compare?
The study provides specific parameter optimizations (optimal levels for current, pulse on time, and pulse off time) derived from statistical analysis to improve productivity when machining SS 316.
What future research is recommended?
Future work could involve exploring different dielectrics, such as distilled water, or investigating Powder-Mixed EDM (PMEDM) to further enhance machining efficiency.
- Citar trabajo
- Sidhant Gupta (Autor), 2016, Experimental Study of MRR, TWR, SR on SS 316 and AISI D2 steel using Aluminium Electrode on EDM, Múnich, GRIN Verlag, https://www.grin.com/document/342374
