A Comparative Study of Corrosion Behavior of Al/SiCp Composite With Cast Iron

Corrosion behavior of LM13 aluminum alloy/silicon carbide particle (SiCp) composite was compared with that of cast iron in three different corrosive media (i.e., mine water, 3.5% sodium chloride [NaCl] solution, and 3.5% sodium hydroxide [NaOH] solution) through the immersion technique. It has been noted that the composite exhibits significantly higher corrosion resistance than cast iron in NaCl solution (marine) and mine water. However, it suffers from higher corrosion rates than cast iron in NaOH solutions. In fact, in NaOH solution, cast iron exhibits insignificant corrosion rates. It has been observed further that the composite exhibits minimum corrosion rates in NaCl media and maximum rates in NaOH solution. Cast iron, however, suffers from the highest corrosion rate in mine water and the least in NaOH solution. In all environments, the corrosion rate of the materials starts reducing after a specific time and finally reaches a stable value. The corroded surfaces of these materials have been studied through scanning electron microscopy and x-ray diffraction, and the mechanism of material removal has been proposed.