Hybrid coatings for aluminium: improved corrosion protection with graphene oxide
Recent studies highlight how hybrid coatings made of epoxy resin, SiO₂, and graphene oxide (GO) can significantly enhance the mechanical and anti-corrosive properties of aluminum. These materials show promise for extending the service life of aerospace components.
A research team has explored the performance of hybrid coatings combining epoxy resin (ER), silicon dioxide (SiO₂), and varying concentrations of graphene oxide (GO). These coatings aim to improve both the mechanical properties and corrosion resistance of aluminum substrates, particularly Al6061-T5.
The coatings were developed using a sol-gel process, where SiO₂ particles were integrated into the ER matrix, which was pre-functionalized with carboxyl groups using abietic acid. Three formulations with 0%, 0.1%, and 0.5% GO were tested. Mechanical tests, including adhesion, pencil hardness, and abrasion resistance, showed significant improvements with a 0.5% GO concentration.
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Focus on Corrosion Resistance and Mechanical Performance
Corrosion resistance was evaluated through electrochemical impedance spectroscopy and salt spray chamber tests. The coating with 0.5% GO demonstrated up to 500 hours of corrosion protection, outperforming those with lower GO content or none. Additionally, abrasion resistance increased by 35%, hardness reached 9H, and the wear index improved by nearly 30%.
The hydrophobic nature of graphene oxide also enhanced the anti-icing properties of the coatings, further showcasing their versatility. These findings underline the potential of epoxy-SiO₂-GO hybrids to extend the durability of aluminum parts, particularly in harsh environments.
Source: Journal of Coatings Technology and Research, Volume 21, Pages 559–574, 2024
