Experimental investigation on the performance improvement of electrochemical machining process using oxygen-enriched electrolyte

This paper investigates the performance enhancement of electrochemical machining (ECM) process by oxygenated aqueous sodium chloride (NaCl) electrolyte. It is experimentally found that the performance parameters such as material removal rate (MRR) and surface roughness (R-a) are greatly improved with this new mix of electrolyte. The oxygen gas is suitable to electrochemically react with aqueous NaCl solution to enhance the oxidation of metal oxides on the machined surface to increase the MRR. In this work, experimental investigations are conducted with both aqueous NaCl electrolyte and oxygenated aqueous NaCl electrolyte on the alloy steel specimen (20MnCr5). Largest MRR of 7.33 g/min with R-a of 1.90 mu m is obtained in oxygenated NaCl environment compared to MRR of 1.98 g/min and R-a of 3.13 mu m in aqueous NaCl environment with machining conditions of voltage (V) of 17 V, tool feed rate (F) of 0.5 mm/min, and electrolyte concentration (EC) of 142.5 g/l of water. Microstructure of surface of the specimen machined with oxygenated aqueous NaCl electrolyte is more homogeneous and promises a good surface quality.