THE CORROSION BEHAVIOR OF ALUMINUM-SILICON CARBIDE COMPOSITES IN AERATED 3.5-PERCENT SODIUM-CHLORIDE

The corrosion behaviour of aluminium 6061-T6 alloy and 6061-SiC composite in 3.5% NaCl was investigated. While alloy 6061 underwent pitting corrosion, the composite material exhibited two types of corrosion: (1) pitting and crevice attack around each SiC fibre, and (2) crevice corrosion in surface voids or hair-line fractures. The pitting and crevice corrosion around the fibres were due to the accumulation of magnesium at the fibre-matrix interface during composite manufacture. The effect of cerium inhibition was also examined with these materials, and was shown to retard pit initiation for approximately 1-2 days.