Impact of Dielectric Conductivity and Other Process Parameters on Machining Characteristics in WEDM of Al 6065 Alloy

Abstract

Among the wire electrical discharge machining (WEDM) parameters, dielectric conductivity plays a crucial role to determine the performance characteristics of the process. In this study, the effects of dielectric conductivity and four other significant process parameters such as pulse on time ([Formula: see text], arc on time ([Formula: see text], servo sensitivity ([Formula: see text], and open-circuit voltage ([Formula: see text] on Al 6065 have been investigated. Experimental result shows that maximum cutting speed is obtained at a 10 mho/m dielectric conductivity ([Formula: see text] setting. It is also found that for a broad range of corner error ([Formula: see text] and surface roughness ([Formula: see text] during single-pass cutting operations, 10[Formula: see text]mho/m conductivity settings give the best result. However, to achieve the corner accuracy and a surface finish lower than the critical limit (i.e., [Formula: see text][Formula: see text]mm & [Formula: see text]m), 4 mho/m conductivity is found to be the best setting. In this concern, a suitable optimization technique is used to prepare a technical guideline for the optimal machining of Al 6065. Additionally, heat-affected zone (HAZ) and surface topography analysis have been carried out to evaluate the characteristics of the WEDM surface. It is observed from the machined surface that the surface is full of discharge craters, micro-voids, and recast globules. On the other hand, HAZ decreases as the conductivity of the dielectric increases.