Investigation on Applicability of Diatomite Powder-Mixed Dielectric Fluid in Electrical Discharge Machining Processes

Abstract

Powder-mixed electrical discharge machining is one of the latest techniques for improving material removal rate and electrode wear ratio among other performance characteristics.  However, its utilization in the manufacturing industry is very low because many fundamental issues of this new development such as machining mechanism, cost effectiveness of powders and powder concentration in the working fluid together with safety and environmental impact among others, are not well understood. The objective of this study was to investigate diatomite as a potential powder for suspension in dielectric fluids of electrical discharge machines. The effect of diatomite powder suspended in distilled water is investigated using a graphite tool electrode on mild steel workpiece. The process parameters used are peak current, pulse-on time and powder concentration. Completely randomized design is used to plan and analyze the experiments which are performed on toolcraft A25 sinker electrical discharge machine with retrofitted dielectric fluid circulation system. Analysis of variance is performed at 5% level of significance. The experimental results show that the suspension of diatomite powder in dielectric fluid improves the performance characteristics of conventional electrical discharge machining process and future research based on these findings  have been outlined.