Study on the influence of auxiliary electrode and magnet on electrochemical machining of SS304 using NaCl and NaNO₃

Abstract

SS304 is a potential material for the use in defense, medical, aerospace, and automotive industries owing to its excellent mechanical and chemical properties. Machining of SS304 is a topic of great research interest and complex shapes can be produced effectively using Electrochemical machining (ECM). However stray corrosion is a problem in ECM that has a negative impact on the process. Moreover, acids are widely used as electrolytes in ECM. The use of eco-friendly electrolytes saves the operator and the environment from the threats associated with the use of acids as electrolytes. Hence in this study, eco-friendly electrolytes (NaCl and NaNO3) are used. This paper presents a study to reduce the adverse effect of stray corrosion using a magnet, an auxiliary electrode, and a combination of both on two eco-friendly electrolytes using SS304 as workpiece. The evaluation was done based on Taper angle, Radial overcut, MRR, Surface roughness, and Radial-Stray current affected zone. The magnet was placed below the workpiece using a 3D-printed fixture. From the experiments conducted it has been found that the use of Aluminum as an auxiliary electrode is effective when using NaCl as an electrolyte. Up to 37% decrease in taper angle and a 63% reduction in surface roughness was observed when machining was done under the influence of a magnet using NaCl, due to the formation of vortex flow in the machining zone.