Experimental investigation and optimization of WEDM process for AISI 420 stainless steel

Abstract

Abstract AISI 420 Stainless steel is martensitic steel having sufficient corrosive resistance and outstanding hardness used for making knife blades, shear blades, hand tools, and surgical instruments for the medical industry. For the machining of this kind of high-strength material, WEDM is a popular advanced machining technique for creating items with complex forms and profiles. WEDM of AISI420 stainless steel is accomplished utilizing Zn coated copper wire as an electrode in this study. Machine input control parameters include pulse on time (Ton), pulse off time (Toff), peak current (Ip), and wire feed rate (Wf), whereas measured output response parameters include material removal rate (MRR), Kerf width (KW), and surface roughness (SR). Experiments were constructed using Taguchi L16 orthogonal arrays, and control parameters were optimized using Taguchi-based grey relational analysis (TGRA). Parametric analyses are done for multi-response optimization by obtaining grey relational grade (GRG). It has been found from the ANOVA table that Ton, Toff, Ip, and Wf are having % contributions of 85.67%, 4.38%, 8.47%, and 0.26% respectively. The optimal level of input parameters obtained by Taguchi-based GRA is Ton 125µs, Toff 40µs, Ip 220A, and Wf 8m/min. To validate the results confirmation tests are performed on optimal input parameters.