Improvement the Corrosion Resistance of Aluminum Bronze Alloy (Cu-7.7wt%Al) Reinforced by Al₂O₃ and TiO₂ Nanoparticles

This work involves study of corrosion behavior of Aluminum bronze alloy (Cu-7.7wt%Al) reinforced by both nanoparticles of Al₂O₃ and TiO₂ with different percentage (0.6, 1.1, 1.5 and 3 weight percent). Composite materials are prepared by stir casting method with mechanical stirring and magnetic field from induction furnace that used in this work. The copper base alloy reinforced samples were tested to investigate corrosion behavior, by using Tafel extrapolation technique. The Scanning Electron Microscope was used to study the effect of Al₂O₃ and TiO₂ nanoparticles on the topography of surfaces. The results showed that the microstructure of reinforced alloy is composed of a fine dendritic structure of α Cu phase and CuAl2 as intermetallic compound. The samples reinforced with 3wt% of Al₂O₃ and TiO₂ have a lower corrosion rate compared to nano-composites reinforced with 1.5wt% of Al₂O₃ and TiO2. While the nano-composites reinforced with 1.5wt% of Al₂O₃ and TiO₂ has lower corrosion rate compared to the Cu-Al matrix in 3.5%NaCl solution at ambient temperature. (paper)