Corrosion resistance of low SiC particle variation at low weight content on 1060 aluminum matrix composite in sulfate-contaminated seawater

Abstract

The effect SiC particle sizes (3 µm, 9 µm 29 µm and 45 µm) at 2.5% weight content on the corrosion resistance of 1060 aluminum in sulfate and sulfate-chloride solution was studied by potentiodynamic polarization, open circuit potential measurement and optical microscopy. Results showed the presence of SiC increases the susceptibility of monolithic aluminum (0 µm SiC particle size) to corrosion. In the sulfate solution, the corrosion rate values increased from 0.074 mm/y to 0.556 mm/y at 3 µm SiC particle size after which a progressive decrease in corrosion rate was observed to 0.240 mm/y at 45 µm SiC particle size. The corrosion rate value in sulfate-chloride solution increased significantly with increase in SiC particle size from 0.580 mm/y (0 µm) to 1.181 mm/y at 45 µm. Open circuit potential plots show monolithic aluminum in both solutions is the most electronegative, though potential transients were quite visible on the plot from sulfate-chloride solution. The surface of the corroded 1060AlSiC specimens agree with the results from electrochemical test with extensive morphological damage. Keywords: Aluminum, Silicon carbide, Corrosion