Electrical Discharge Machining of AISI 329 Stainless Steel Using Copper and Brass Rotary Tubular Electrode

Abstract

In the present study, the performance parameters of EDM process has been evaluated to achieve the feasibility in drilling of AISI 329 stainless steel which is extensively used in several industrial applications, e.g., heat exchangers, chemical tanks, pressure vessel parts, compressor parts, and seawater desalination plants. The selection of EDM control parameters largely depends on the material combination of electrode and work-piece. EDM manufactures only supply these control parameters for a limited number of material combinations. The present experimental work exhibits the optimum selection of control parameters (i.e., pulse current, pulse duration, pulse off time, and dielectric pressure) to maximize the material removal rate and minimize the electrode wear rate and taper angle of the hole simultaneously using hybrid optimization technique. The comparative investigation of copper and brass electrode revealed that copper electrode improves the hole quality and exhibits good machinability compare to brass electrode. It was observed that brass electrode wears rapidly because its high electrical resistivity, low melting point and low thermal conductivity compare to copper electrode. The most dominant parameters affecting the performance of EDM process has been evaluated using ANOVA. Further, the confirmation experiment shows a good agreement with the predicted value.