Effect of processing conditions and electrode materials on the surface roughness of EDM-processed hybrid metal matrix composites

The current investigation aims to investigate the role of four major input parameters, i.e. Current (I), Gap Voltage (V), Pulse off time (T_off), and Pulse duration (T_on) on surface roughness (R_a) of Al–Mg-0.6Si-0.275Cu/SiC10 % hybrid composite samples fabricated by Stir-casting. In addition, paper focuses on the goal to ascertain the impact of distinct tool materials on surface morphology of Al/SiC composite. Further, mathematical models were developed using the L₂₉ orthogonal array in the Stat-Ease Modelling Expert V7.0 software. Thus, to validate the significance of the developed models, an Analysis of Variance was used. Finally, the topography of the specimen's surface (pre and post-machining) was performed using scanning electron microscopy (SEM). The results showed that at a peak current of 5 Amp, Gap voltage of 100V, Pulse on time of 100 μs, and Pulse off time of 40 μs, the lowest surface roughness with brass and copper electrodes was 0.29 μm and 0.32 μm obtained. The Brass electrode yielded 9.3 % lower surface roughness than the copper electrode.