Optimization of wire electrical discharge machining parameters to improve the surface roughness of laser-cladded Stellite 6 on AISI 1018 steel

Abstract

This study investigated the wire electrical discharge machining (WEDM) machinability of Stellite 6 laser cladded AISI 1018 structural steel, a material combination that is practically unexplored in WEDM literature. Two Taguchi L9 orthogonal array experiments were conducted: Experiment 1 examined mean voltage (VM), pulse-on time (T _on ), pulse-off time (T _off ), and wire tension; Experiment 2 examined wire feed, water pressure, wire tension, and speed limit. Signal-to-noise (S/N) ratio analysis and ANOVA were applied to identify the dominant parameters. Mean voltage was the most influential factor in Experiment 1 (ANOVA contribution: 73.89 %), while wire feed governed surface roughness in Experiment 2 (36.04 %). Optimal parameter combinations yielded minimum Ra values of 2.224 μm and 2.515 μm, both validated within the 95 % confidence interval, confirming the effectiveness of Taguchi optimization at the 0.05 significance level. The results demonstrated that WEDM is a viable and efficient post-processing route for laser cladded Stellite 6 components, with process parameters requiring careful selection to account for the heterogeneous carbide microstructure of the coating.