Reducing the surface roughness of curvature surfaces by electrical discharge machining with magnetic abrasive finishing

This study presents an integrated work that combines unconventional machining and finishing techniques for complex geometric models. A Taguchi design investigated three electrical-discharge parameters—electric current, pulse duration, and gap—each at three levels; a multi-objective optimization matrix was then used to select the optimal conditions. The geometric models were designed using SolidWorks software and machined on a CNC machine to ensure maximum accuracy in the resulting samples. The samples were finished using the magnetic abrasive finishing technique, where the particle mixture was developed as a hybrid blend of two types of abrasive particles, tungsten carbide (WC) and silicon carbide (SiC). Among the electrical discharge machining factors, electric current showed the highest influence, yielding a maximum metal removal rate of 25.1024 mm³/min at Ip = 42 A, Tn = 300 µs, gap = 8 mm, and the minimum roughness of 11.6674 µm at Ip = 24 A, Tn = 150 µs, gap = 5 mm. The magnetic abrasive finishing stage substantially improved the surface quality of the complex models, reducing roughness from 11.9169 µm to about 4.29 µm, equivalent to a 64.02% reduction. Within finishing, feed rate was the most influential variable, followed by spindle speed, while particle size had the least effect. Overall, the combined methodology improves process performance and post-process surface quality for complex geometries while identifying the dominant parameters that govern material removal and roughness outcomes.