Influence of Al2O3 and SiO2 nano-particles on hardness and corrosion resistance of aluminum alloy (Al-4.5%Cu-1.5%Mg)

Abstract

In the current work, the influence of a single and hybrid addition of the nano-particles (Al2O3) and (SiO2) on the corrosion resistance and polarization of the aluminum alloy (Al-4.5 wt%Cu-1.5 wt%Mg) as base alloy was investigated. Many composites reinforced with an individual addition of (5 wt%) SiO2 or (5 wt%) (Al2O3) nano-particles and hybrid addition of (2.5 wt% SiO2 + 2.5% Al2O3) nanoparticles were fabricated using powder metallurgy route. The rate of corrosion was evaluated by the Tafel polarization extrapolation method. Results showed that the hardness of nano composites that reinforced with the nanoparticles was higher than unreinforced base material. It was found that rate of corrosion of the hybrid nano-composite was lower than nano-composites with single addition and base alloy sample in the (3.5%NaCl) solution. Also, the results revealed that the pitting corrosion resistance is improved with the Al2O3 and/or SiO2 nano-particles addition during the cyclic polarization by disappearing the loop of hysteresis from the anodic polarization region.