Influence of spark gap in EDM based on Buckingham’s π theorem

• Main Author: Toh, Jyh Yong.
• Other Authors: Yeo Swee Hock
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Mechanical engineering::Control engineering
• Online Access: http://hdl.handle.net/10356/54003
• Institution: Nanyang Technological University

This project aims to highlight the importance of spark gap in EDM and Powder Mixed Dielectric EDM (PMEDM) in relations to surface roughness. Two output, spark gap and surface roughness were examined through Buckingham’s π theorem, a form of Dimensional Analysis tool, being the most important part of the project. This tool was utilized to denote on the most influential parameters and sub parameters that influence spark gap and further elaborate on the influence of spark gap in surface roughness. Experiments were done in EDM and PMEDM, using SKD-11 steel work piece and copper rod electrode. In PMEDM, silicon carbide powders were added to dielectric fluid to further enlarge the spark gap. These experiments were used to compare with the formulated equation from Buckingham’s π theorem to determine the accuracy of these equations in relation with the experimented data. With a highly accurate formulated equation, the influence of spark gap in surface roughness can be analyzed by the SEM data collected. To conclude, spark gap has a great impact in surface roughness which is a basic parameter of length in dimension, created by variation of discharge voltage, current and time. Discharge voltage being the most influential parameter. This observation may further enhance the surface finish in EDM field, such as precision engineering.