Corrosion Behavior of SiC / Al Metal Matrix Composites

Abstract

The effect of the phase on the corrosion behavior of metal matrix composites has been studied in , both in the presence and absence of dissolved oxygen. Anodic polarization behavior has been determined, and pitting potentials have been measured for three composite systems: 2024, 6061, and 5456. General corrosion behavior and the effects of anodizing on the corrosion resistance of the composites have been studied by a‐c impedance techniques. The results show that pitting susceptibility is about the same for the composites and their corresponding alloys, except for Al 2024. In this system, the composite is less resistant to pit initiation than the corresponding wrought aluminum alloy. General corrosion is more significantly affected by the presence of oxygen than by the phase. In the absence of oxygen, corrosion resistance is improved for both the alloys and composites. In addition, the corrosion resistance of the composites can be improved by anodizing.