Machining Complex Profile on Nickel-Aluminum-Bronze Alloy through Wire Electric Discharge Machining Process using Zinc-Coated Brass Wire

WEDM is efficient in machining complicated profiles with high dimensional accuracy. The Nickel-aluminum-bronze (NAB) is a high-strength alloy with exceptional corrosion-resistant properties and is abundantly used in marine applications such as propellers, valves, and seawater pumps. The previous literature reports numerous instances of WEDM-induced simple profiles on NAB alloy employing brass and molybdenum wires; however, the WEDM of detailed profiles on NAB alloy using brass wire encapsulated with zinc layer is scarce to find. Hence, in the present article, we proposed an experimental framework to create complex profiles on NAB alloy using the zinc-enveloped brass wire in the WEDM process. The control variables, namely the pulse on time, servo voltage, current, and pulse off time, were varied to report their influence on the experimentally determined machining time (MT), kerf width (KW), and corner error (CE). The statistical analysis revealed that pulse on time affects the KW and CE dominantly, whereas the current has high relative significance when MT is concerned. FESEM images showed that WEDM processing at high discharge energy settings generated many large-sized voids, large melted deposits, deep craters, and microcracks on the surface. Conversely, WEDM processing at low discharge energy settings caused small-sized voids, small melted deposits, and shallow craters. Microcracks are not visible on the surface after WEDM processing at a low discharge energy level. Energy dispersive x-ray (EDX) analysis discerned the substantial deposition of zinc on the machined surface from the zinc-coated brass wire ensuing the machining operation.