The corrosion behaviour of the aluminum alloy 7075/SiCp metal matrix composite prepared by spray deposition

Abstract

Abstract Aluminum alloy 7075 and 7075/SiCp (MMC) were prepared by multi‐layer spray deposition method and the corrosion behaviour of them were studied by electrochemical measurements to study the effect of the addition of silicon carbide on the corrosion behaviour of the MMC. The electrochemical noise result shows that the amplitude of the potential noise of the composite is lower than that of the spray deposited 7075 alloy. The potentiodynamic polarization curves results show that both the cathodic oxygen reduction current density and the anodic dissolution current density of the 7075/SiCp MMC are less than those of the 7075 alloy. Thus, the addition of SiC particles increases the corrosion resistance of the MMC. This may be due to that the microstructure of the spray deposited MMC is compact and SiC particles are nonmetallic material, the addition of it minimizes the real corrosion area of the alloy.