Corrosion damage evolution and mechanical properties of carbon fiber reinforced aluminum laminate

Abstract

Fiber metal laminates (FMLs), a kind of lightweight material with excellent comprehensive performance, have been successfully applied in aerospace. FMLs reinforced with carbon fiber have better mechanical properties than those with glass or aramid fiber. However, carbon fiber binding metal may lead to galvanic corrosion which limits its application. In this paper, electrochemical methods, optical microscope and scanning electron microscope were used to analyze the corrosion evolution of carbon fiber reinforced aluminum laminate (CARALL) in corrosive environment and explore anti-corrosion ways to protect CARALL. The results show that the connection between carbon fiber and aluminum alloy changes electric potential, causing galvanic corrosion. The galvanic corrosion will obviously accelerate CARALL corroded in solution, leading to a 72.1% decrease in interlaminar shear strength, and the crevice corrosion has a greater impact on CARALL resulting in delamination. The reduction of interlaminar shear strength has a similar linear relationship with the corrosion time. In addition, the adhesive layers between carbon fiber and aluminum alloy cannot protect CARALL, while side edge protection can effectively slow down corrosion rate. Therefore, the exposed edges should be coated with anti-corrosion painting. CARALL has the potential to be used for aerospace components.