Wire EDM machining characteristics of squeeze cast Al-Zn-Mg-Cu/(SiC + Al 2 O 3 ) hybrid composite by TOPSIS approach

Abstract

This research focuses on the squeeze-cast Al-Zn-Mg-Cu metal matrix reinforced with 10% silicon carbide and 10% aluminium oxide particles machined by wire-cut electro-discharge machining (WEDM) to examine the consequences of input factors like pulse-on time, current, pulse-off time, and wire speed over the responses of metal removal rate (MRR) and surface roughness. The pulse-on time (7–11 µs), current (2–4 amps), pulse-off time (6–10 µs), and wire speed (1–3 m/min) used during WEDM machining are all variable. The TOPSIS approach was utilised to identify the optimal processing settings. According to the optimised findings, larger MRR of 3.95 mm³/min and reduced surface roughness of 3.295 µm were achieved by combining pulse-on time, current, pulse-off time and wire speed at 7 µs, 2 amp, 6 µs and 1 m/min, respectively. With a scanning electron microscope, the machined surfaces are examined. Based on the study of the machined surface, the micrograph of sample order no. 1, which has relatively less hills and gorges, has a t_on of 7 µs, t_off of 6 µs, current of 2 amps and wire speed of 1 m/min. Under a microscope, the amount and size of the craters and fractures created appear to be decreasing. The moderate current intensity and low pulse-off time result in a reduction in the intensity of the electrical discharge. This enhances the surface finish since there are fewer, smaller craters and fissures. The obtained findings may be used by the manufacturers to improve WEDM machining of Al 7075 reinforced with SiC and Al₂O₃ particles.