Effect of Milling and Wire Electric Discharge Machining on Recast Layer Formation and Tensile Behavior of Metallic Materials

ABSTRACT Machining of materials is an invaluable technique to give specific shapes and dimensions of desired materials. Different machining processes give rise to different surface characteristics that include not only surface roughness but also specific surface morphology, such as the recast layer. This research study focuses on the effect of two different machining techniques: (i) milling and (ii) wire electrical discharge machining (wire–EDM) on the tensile behavior, surface integrity, and fractography of aluminum (Al‐6061), Al‐based metal matrix composites (Al‐MMC with 10% SiC), duplex stainless steel (DSS‐2205), and titanium (Ti‐6Al‐4V). The appearance of the surface produced from wire–EDM had similar features, regardless of material, but the machining marks were visible in different degrees on the considered workpiece materials. Recast layer thickness depends on materials' property, where no recast layer was noted for Al and maximum thickness was noted in DSS‐2205. For all of the materials investigated, the surface roughness of the specimens fabricated by wire–EDM was always higher than that of milling, although it implicates negligible difference in the tensile strength of the materials except Ti6Al‐4V, where the stiffness increased, and ductility reduced significantly, due to wire–EDM. The presence and extent of recast for a given material implied a profound effect in both tensile strength and percentage elongation. The fracture mechanism was ductile all through the fracture surface, except in the re‐cast layer region.