Simulation Study Of The Current Density Distribution For Combined Electrodes In Micro-EDM

Micro-EDM has a wide spectrum of applications and it holds great impact on manufacturing industry.In Micro-EDM,electrode wear is serious,especially in the sharp edge or corner part.The reason is when a high frequency current normally carried out in MicroEDM passes through a conductor,it induces a skin effect in it that disturbs the current density distribution of the conductor.Based on this principle,this research proposed a circular combined electrode structure having an outer sleeve and inner cylindrical electrode in order to manipulate the current density distribution.The aim of this research is to study the impact of current density distribution on tool wear of combined electrode based on electromagnetic theory.A combined electrode model is designed and a series of FEA simulations are carried out to study the variation of current density distribution for affecting parameters.Results showed that the skin effect can be minimized and the current density distribution can be made uniform throughout the electrode.In this way,edge wear of electrode can be hindered.To justify these results,an experimental approach is designed based on Taguchi analysis,which created all the possible combinations of parameters for the experiment.A circular combined electrode was fabricated and subjected to EDM milling operation.Later,upon analysis this electrode showed a conical shape wear instead of straight wear,which justified that the wear of sleeve electrode was less as compared to cylindrical electrode.Therefore,the results showed the possibility of fabricating such combined electrodes that can wear less improving the machining efficiency of process.