WEDM with different diameter wire electrodes on Inconel 718: Improved dimensional deviation, wire consumption and surface quality

Abstract

Inconel 718, a rich nickel content alloy, has been widely adopted for high-temperature applications across industries. A recently explored non-conventional machining method, wire electrical discharge machining (WEDM), is suitable for machining these alloys. However, the dimensional inaccuracy, high consumption of wire tool electrodes and poor surface quality affects precision and productivity. This study aimed to investigate the effect of employing different wire diameters in WEDM and influence on performance characteristics such as the dimensional deviation, overcut, wire consumption, surface roughness, recast layer thickness, micro hardness, microstructural and metallurgical changes. For small wire diameters compared to large wire diameters, a significant reduction in the dimensional deviation and overcut is incurred. With average-sized craters, a surface machined using a small-diameter wire showed enhancement, decreased changes in micro-hardness, and lower recast layer thickness than a surface machined using a large-diameter wire. For the prediction of surface roughness, a model was developed considering wire diameter. In addition, wire consumption for smaller wire diameters is reduced, encouraging cost-efficiency, and solving problems with waste disposal. The Inclusion of smaller-diameter wires in WEDM has increased the precision with productivity, promoted reduction in the wire and workpiece waste, and has a lower environmental impact.