Process optimization for rapid manufacturing of complex geometry electrical discharge machining electrode

Abstract

Rapid manufacturing techniques permit tools and dies to be fabricated in short duration of time with complex geometry. The major contribution of the present research was to fabricate copper complex geometry electric discharge machining electrode by using amalgamation of three-dimensional printing along with pressureless loose sintering. Response surface methodology was employed to study the sintering parameters’ (sintering temperature, heating rate and soaking time) effect on electric discharge machining electrode important characteristics such as density, shrinkage and electrical conductivity. Analysis of variance was used to investigate the significant contribution of the parameters on the responses. Density and electrical conductivity of fabricated electric discharge machining electrode were revealed to increase with respect to rise in soaking time and sintering temperature. The interaction between the heating rate and sintering temperature for density and electrical conductivity responses signified the less effect of heating rate at high temperatures. Further, multi-objective optimization was used to maximize density and electrical conductivity and to minimize volumetric shrinkage. Different shapes of electric discharge machining electrodes were fabricated at optimized parameters. In addition, the fabricated electrodes were tested on electric discharge machining of D2 steel for 5 mm depth. The dimensional analysis was carried out between the computer aided design (CAD) model, fabricated electric discharge machining electrode and the obtained cavity by electric discharge machining process. The results depicted high efficacy of the process to fabricate complex geometry electric discharge machining electrodes.