Parameter Optimization of Wire EDM using Low Frequency Vibrations

Electrical Discharge Machining (EDM) is a non-contact machining process, which electrically removes material from any conductive workpiece. This is achieved by applying high frequency pulsed current to the workpiece through a tool electrode immersed in a dielectric fluid which subsequently melts and vaporizes the workpiece material [1–4]. Unlike the traditional machining method, EDM offers many advantages, for instance, it can be used to machine very complex shape by using a simple tool electrode. In addition, the ease of machining in EDM process is only depending on the λ · θ · ρ theory, which is the product of thermal conductivity (λ), melting point (θ) and electrical resistivity (ρ) of workpiece material. As a product of electrical discharge, debris are created and accumulated in the sparking gap between the tool electrode and the workpiece. If the amounts of debris in the machining gap are too large, reduction of resistance occurs and encourages the formation of abnormal discharges, which leads to significant tool wear and slows down the material removal rate.