Title: Investigation into micro-hole geometrical accuracy during micro-EDM of Ti-6Al-4V employing different dielectrics
Authors: G. Kibria; B. Bhattacharyya
Addresses: Department of Production Engineering, Jadavpur University, Kolkata, 700 032, India. ' Department of Production Engineering, Jadavpur University, Kolkata, 700 032, India
Abstract: Micro-electrical discharge machining (micro-EDM) is a non-contact type advanced machining process (AMP) in which removal of material from workpiece takes place by thermo-erosion mechanism between the micro-tool and workpiece within a small gap. The present study attempts to make comparative investigation of micro-hole machining process in EDM for using three different dielectrics such as pure kerosene, pure de-ionised water and boron carbide mixed kerosene and de-ionised water. The two most important process parameters, i.e., peak current and pulse-on-time were varied keeping other parameters as constant. The experimental results revealed that B4C mixed dielectrics result in non-uniformly circular micro-holes compared to pure kerosene and de-ionised water. Moreover, when de-ionised water is used, powder mixed dielectric results in generation of accurate micro-hole with respect to taper and circularity. Analysis has also been made with the help of optical and SEM micrographs to show the influence of different dielectrics on the micro-hole geometrical accuracy, i.e., hole taper and circularity.
Keywords: micro-EDM; electrical discharge machining; Ti-6Al-4V; micro-holes; de-ionised water; hole circularity; electro-discharge machining; kerosene; boron carbide; micromachining; hole taper.
International Journal of Machining and Machinability of Materials, 2011 Vol.10 No.4, pp.310 - 325
Received: 27 Aug 2010
Accepted: 18 Oct 2010
Published online: 14 Oct 2011 *