Abstract

This paper presents the results obtained and the discussion made from a series of corrosion experiments involving aluminum alloy (LM 13) reinforced with Nano-ZrO2, size of the particles dispersed varies from 100 to 200 nm and amount of addition varies from 3 to 15 wt.% in steps of 3 wt.%. The resulting CNMMCs are solidified under the influence of copper chill of 25 mm thickness to study the effect of corrosion behavior. The corrosion test employed was the electrochemical polarization method according to ASTM G59-97 (2009) standards. Corrosion resistance was found to increase significantly with increase in ZrO₂ content in chilled CNMMCs. Nevertheless, even with high ZrO₂ content corrosion attack, that is, pitting was found to be most severe during the initial stage of each test but it invariably decreased to a very low value in the later stages, due to the formation of an adherent protective layer on the CNMMCs developed. Scanning electron microscopy (SEM) studies of the corroded surface were also examined to study the mechanism of corrosion.

Key words: Nano, corrosion, chill, composite, solidification, microstructure.