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

Abstract

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.

Electrochemical behaviour of graphene and alumina whisker co-reinforced copper matrix composites

“…The chemical stability and impermeability of Al 2 O 3 whiskers and graphene in the composite can shield them from corrosion, as shown in Figure 4, and no corrosion products, such as attached oxide films, were found on the surfaces of alumina and graphene. Cu–Al alloys reinforced by Al 2 O 3 and TiO 2 nanoparticles reportedly have a lower corrosion rate than the Cu–Al matrix [27]. In the 6063 Al matrix composite, the existence of TiC and Al 2 O 3 particles refined the grains of the matrix and induced chloride ions to erode the grain boundary region as the primary site for pitting [28].…”

“…No. matrix [27]. In the 6063 Al matrix composite, the existence of TiC and Al 2 O 3 particles refined the grains of the matrix and induced chloride ions to erode the grain boundary region as the primary site for pitting [28].…”

Study on corrosion resistance of copper matrix composites reinforced by Al2O3 whiskers

“…In addition, Al 2 O 3 whiskers will increase the self-corrosion potential of copper matrix composite materials, making the materials vulnerable to pitting attack. Bragaglia et al [17] studied the effect of Al 2 O 3 strengthening and precipitation on the corrosion behavior of metal matrix composites, and pointed out that the comparison with data of unreinforced alloys confirmed that the presence of alumina has a small improvement in corrosion resistance [27]. Although pitting begins with the reinforcement phase/matrix, as the content of alumina whiskers increases, alumina, graphite, etc are exposed outside the matrix, which will limit the electrical connection between the intermetallic compound particles and the solution, and thus the reaction speed can be slow down.…”