Multi Parametric Optimization of WC-Co Composites Using Desirability Approach

Abstract

Wire electrical discharge machining (WEDM) plays an important role in the manufacturing industry owing to its ability to generate intricate and complex shapes on workpiece with high dimensional accuracy and surface finish. Tungsten carbide cobalt (WC-Co) metal matrix composites (MMC) commonly finds applications as tool and die materials. Yet due to complex stochastic nature of WEDM process and the involvement of high number of input variables the full potential of the process has not been realized. In this present article material removal rate and surface roughness of the Tungsten carbide-cobalt (WC-Co) composite material subjected to wire electric discharge machining was studied. A 0.25 mm diameter zinc coated copper wire was applied as tool electrode to cut the material. Experiments were designed and conducted using Taguchi's L’32 orthogonal array. Experiments were conducted under different combinations of input variables such as percentage of cobalt in the composite, pulse on time, delay time, wire feed, wire tension, ignition current and di-electric pressure. Three trials were conducted and the average was chosen as the response at that particular experimental condition. Optimization of the multiple process variables were carried out using desirability function analysis. Confirmation experiments were carried out to check the accuracy of the optimized results.