Optimization of Electrical Discharge Machining parameters to enhance the machining performance and surface quality of AZ31 magnesium alloy used in biomedical applications

Electric Discharge Machining (EDM) is an advanced machining technique widely used for processing materials that are difficult to machine due to requirements of effective precision and surface finishing that is not possible using conventional methods. Among these materials, magnesium alloys like AZ31 requires more precise machining and desirable surface integrity due to its considerable attention in biomedical applications due to their excellent biocompatibility, biodegradability, and mechanical properties. This study investigates the EDM machining characteristics of AZ31 magnesium alloy in achieving precise machining and desirable surface integrity. The machining performance was evaluated using material removal rate (MRR), electrode wear rate (EWR), and electrode wear ratio (EW ratio). Experiments were conducted using a copper electrode by varying current (2–6 A), pulse-on time (Ton: 2–7 s), pulse-off time (Toff: 1–2 s), and voltage (15–25 V). The experimental design was developed using Taguchi’s L18 orthogonal array, and Analysis of Variance (ANOVA) was applied to identify the most influential machining parameters. The results indicate that current and voltage significantly influence both MRR and EWR, while Ton strongly affects spark energy intensity. The optimal machining conditions for maximizing MRR and minimizing electrode wear were identified as 6 A current, 25 V voltage, 7 s Ton, and 2 s Toff. The improved surface morphology obtained under optimal EDM parameters may support further investigations for potential biomedical applications. Scanning Electron Microscopy (SEM) analysis confirmed enhanced microstructural integrity with reduced microcracks. The findings demonstrate that EDM is an effective technique for machining and surface finishing of AZ31 magnesium alloy.