Corrosion Behavior of A356/SiC Alloy Matrix Composites in 3.5% NaCl Solution

The corrosion behavior of the A356 (0, 5, 10, and 15 wt.%) SiC composites produced by mechanical alloying (MA) and uniaxially pressing/sintering route was studied through electrochemical and surface analysis techniques in 3.5 wt.% NaCl. The corrosion behavior of the samples was investigated by using electrochemical techniques. The corrosion resistance for the unreinforced A356 aluminum alloy was higher than the composites, however, when the A356 aluminum alloy was reinforced with SiC particles, composites were susceptible to a localized type of corrosion at the matrix/SiC particles interface. This made that although the passive zone for composites was wider with a pitting potential value slightly higher than those for base alloy, passivation current density was higher.