Preliminary Experiment of EDM Wire Cut on AZ31 Magnesium Alloy

Abstract

The AZ31 magnesium alloy has become quite popular in the aerospace industry as well as in the automotive sector because of its high strength‐to‐weight ratio and corrosion resistance properties. However, the magnesium alloy's tendency for being highly reactive, having low thermal stability, and ignitability causes conventional machining processes to be quite challenging. Wire electrical discharge machining (WEDM) is a non‐contact machining technique that can serve this purpose by using sparks of electricity to remove material from the workpiece. Nonetheless, very few studies have focused on understanding the effects of the WEDM process parameters on the machinability of AZ31 magnesium alloys. This study examines the preliminary effects of three key WEDM parameters, T on , T off , and SV, on the machining of AZ31 magnesium alloys. The experiments were performed on the FANUC series of wire EDM machines using a 0.25 mm wire electrode made of brass under two parameter conditions, one representing low discharge energy and the other representing high discharge energy. The surface roughness was evaluated by utilizing a Mitutoyo SJ‐310 surface roughness tester, and the machining time was determined by obtaining the value directly from the machine interface. The experimental result shows that lower energy ( T on  = 10 µs, T off  = 12 µs, SV = 15 V) led to a smoother surface finish, that is, a surface roughness of 4.012 µm and lower machining time, 91 s, as compared to higher energy, which gave a surface roughness value of 4.605 µm with machining time of 201 s. From these experimental results, it can be observed that the AZ31 magnesium alloy is extremely susceptible to excess discharge energy during WEDM, resulting in increased thermal erosion and poor surface finish. The initial results obtained from this experiment will prove valuable in future studies for optimizing the machining process statistically by employing the Taguchi method.