Enhancing the performance of electrochemical machining of 20MnCr5 alloy steel and optimization of process parameters by PSO-DF optimizer

Abstract

Electrochemical machining (ECM) of metals, particularly steels, plays an important role in numerous industrial applications. The alloy steels especially 20MnCr5 are used as good wear resistant in the applications of boxes, piston bolts, spindles, camshafts, gears, shafts and other mechanical controlling parts. Machining of above complicated shapes with conventional machine tools is cumbersome task. Hence, investigation was made to study the electrochemical machining characteristics of 20MnCr5 alloy steel. Hydrogen peroxide (H2O2) mixed aqueous NaCl was used as electrolyte in order to enhance the machining performance of ECM. The predominant ECM process parameters such as applied voltage (V), inter-electrode gap (IEG) and electrolyte concentration (EC) were considered to study its influence on the material removal rate (MRR) and surface roughness (Ra). Microstructure of surface of the 20MnCr5 steel specimen machined with ECM was studied to understand the effect of electrolyte during the machining. The contour plots were generated to study the effect of process parameters as well as their interactions. The optimized machined conditions found with particle swarm optimization (PSO)-desirability function (DF) optimizer were quite close with experimental results. Additional advantage of H2O2 presence was noted that scales formed on flow path of electrolyte were completely removed.