The effect of SiCp reinforcement on the corrosion behaviour of Al based metal matrix composites

In this study, the effect of SiC particle volume fraction on the corrosion behavior of Al-Si-Mg based SiCp reinforced metal matrix composites in both aerated and deaerated 3.5 wt.% NaCl aqueous solutions has been investigated. Composites reinforced with 10 and 20 vol.% SiC particles were produced by compocasting technique and then extruded. The corrosion susceptibility was analyzed by measuring the cyclic potentiodynamic polarization. The corrosion rates of the samples were determined by using E-pit, E-corr and i(corr) values obtained from polarization curves. The surface morphology of the composites was determined by an optical microscopy and scanning electron microscopy (SEM). In addition, X-ray diffraction (XRD) technique has been used in order to determine the phases occurring at the matrix/SiC interface. The obtained results indicate that the corrosion resistance of the composites decreased with increased SiC particle content