Fabrication and Corrosion Behaviour of Aluminium Alloy (LM-13) Reinforced with Nano-ZrO 2 Particulate Chilled Nano Metal Matrix Composites (CNMMCs) for Aerospace Applications

Abstract

This research presents the results obtained and the discussions made from a series of corrosion experiments involving aluminum alloy (LM 13) reinforced with Nano-ZrO 2 , size of the particles dispersed varies from 100-200 nm and amount of addition varies from 3 wt% 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 inZrO 2 content in chilled CNMMCs. Nevertheless, even with high ZrO 2 content corrosion attack i.e., pitting was found to be most severe during the initial stages 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. SEM studies of the corroded surface were also examined to study the mechanism of corrosion. Present research is un-dertaken to develop a corrosion resistant composite for aerospace application where aluminum is highly suspected to corrosion.