Electric Discharge Machining of Tungsten Carbide using Uncoated and Coated Wire Electrodes: Analysis of Cutting Speed and Workpiece Geometrical Accuracy

Abstract

Tungsten carbide is an important tool and die material due to its excellent mechanical properties such as high hardness, good toughness, and wear resistance. Wire electric discharge machining (WEDM) is regarded as a process capable of machining complex geometries and curved features in difficult-to-cut tungsten carbide. The present research work is carried out to study the influence of wire electrode, workpiece taper angle, and WEDM parameters on cutting speed and geometrical error of curved profile machined in tungsten carbide. Experiments are performed based on Taguchi's L18 orthogonal array using two types of wires; uncoated brass wire and zinc-coated brass wire. Experimental results indicate that zinc-coated brass wire offers higher cutting speed as compared to uncoated brass wire. Main effects plots show that pulse-on time and pulse-off time are the most significant factors affecting cutting speed while taper angle is the most significant factor for geometrical error.