Taguchi Optimization of MRR in Magnesium AZ91 Using EDM with Graphite Electrode

Abstract:

This study investigates the performance of Electrical Discharge Machining (EDM) on magnesium alloy grade AZ91 using a graphite electrode, with a focus on optimizing the material removal rate (MRR) and electrode wear ratio (EWR). The machining parameters such as current, on-time, and duty factor were systematically varied and assessed using the Taguchi method with an L9 orthogonal array design. The results identified current and on-time as significant factors influencing both MRR and EWR. Higher current values led to increased MRR, enhancing material removal efficiency, but also resulted in greater electrode degradation. Similarly, increased on-time durations significantly impacted MRR and EWR, indicating that prolonged exposure to discharge conditions can improve material removal while contributing to higher electrode wear. Conversely, the duty factor did not show a statistically significant impact on either MRR or EWR within the experimental conditions of this study.

• Periodical: Key Engineering Materials (Volume 1014)
• Pages: 11-16
• DOI: https://doi.org/10.4028/p-1kPPWg
• Online since: June 2025
• Authors: Patittar Nakwong, Apiwat Muttamara*
• Keywords: Electrical Discharge Machining (EDM), Graphite Electrode, Magnesium AZ91, Taguchi Optimization

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