Material Removal Rate and Surface Roughness of SiC/Al Matrix Composites Machined by Wire Electrical Discharge Machining: Experimental Method

Abstract

In the present study, the experiments have been made to investigate the effect of wire electrical discharge machining (WEDM) parameters such as pulse duration, pulse off time, discharge current , working voltage on the material removal rate and the surface roughness (Ra) during WEDM of particulate silicon carbide aluminum (SiC/Al) metal matrix composites. It was found that the material removal rate and the surface roughness of the SiC/Al matrix composites with the SiC content of wt.10% SiC/Al is higher than the SiC content of wt.5%. The removal rate increases with the increase of discharge current; and first increases with the pulse duration, when the pulse duration reaches 11μs, the removal rate shows a slow downward trend. The material removal rate decreases with the values increase of pulse off time and working voltage. The surface roughness of the work piece increase with the increases of pulse duration and discharge current, while the effect by pulse off time and working voltage is not significant. The surface morphology was observed by SEM, found that the surface of SiC/Al matrix composites by WEDM is mainly composed of molten recasting layer, little ball of different diameters, pits, holes and a few micro fissure. Keywords-Sic; Al Matrix Composite; WEDM; Parameters; Material Removal Rate; Surface Roughness