Pitting Corrosion of 15vol.%SiCw/AA2124 Composites

초록

The corrosion behavior of 15vol.% SiCw reinforced AA2124 metal matrix composites(MMCs) were investigated in a 3.5wt.% sodium chloride solution by potentiodynamic polarization measurement and galvanic corrosion test between SiC reinforcing material and AA2124 alloy of matrix composition. Pitting potentials of MMCs and AA2124 matrix alloy were obtained by -0.69V(vs. SCE) of equivalent value. However, pitting potential of MMCs was almost same as corrosion potential, and pitting susceptibility of MMCs was higher than AA2124 alloy. According to the result of galvanic corrosion test, potential of matrix increased to pitting potential by this galvanic coupling effect and thus, pitting occurred easily in MMCs than in AA2124 alloy of matrix composition.