The Corrosion Behavior of Graphene-Reinforced Al Matrix Composites in 3.5 wt.% NaCl Solution

In recent years, graphene has been used as a reinforcing element to develop thermal, tribological, and mechanical properties of aluminum matrix composites due to its extraordinary properties. Although there are many studies on graphene-reinforced aluminum and its mechanical properties in the literature, the number of detailed corrosion studies with the electrochemical impedance spectroscopy (EIS) method for graphene-reinforced aluminum is few. Pure aluminum and aluminum-graphene composites with various contents (0.1 and 0.5 wt.%) were fabricated via the powder metallurgy route. The microstructures and corrosion resistances of the prepared samples were investigated by the scanning electron microscope and electrochemical impedance spectroscopy. The corrosion experiments were performed in 3.5 wt.%NaCl solution at 28 °C with saturated calomel reference electrode and platinum auxiliary electrode. From the EIS corrosion test results, the AlGr05 sample had maximum corrosion resistance of 2.985 Ω cm2. The Tafel polarization method results showed that the AlGr05 sample (0.0051 mA/cm2) had the lowest corrosion flow rate. Also, the SEM images of the corrosion samples showed that the highest cohesion of constituent particles, the least amount of corrosion, and particle separation were observed at Al-0.5 wt.%graphene. In conclusion, the highest corrosion resistance among specimens was obtained at Al-0.5 wt.% graphene composite.