Corrosion inhibitor from nature: Fundamentals of tannic acid inhibition for AA2024 alloy
Rubén del Olmo, A.C. Bastos, K.A. Yasakau, Alesia Sushkova, R. Arrabal, João Tedim
Abstract
This study addresses the fundamentals of corrosion inhibition of AA2024 alloy by tannic acid (TA), a Cr-free and eco-friendly natural product. To this end, the AA2024 alloy was immersed in NaCl solution (50 mM) with different TA concentrations (0.1–10 mM) for 7 days. Surface (SEM, Raman, and SKPFM) and electrochemical analyses (EIS, PDP, and SVET) revealed mixed inhibition after 1 day of immersion in TA solution. Long-term immersion tests in TA solutions produced a tannate-rich oxide film on the surface. The films with low tannate content (formed in 0.1 and 1 mM TA) showed the highest stability and corrosion resistance.
Topics & Concepts
Tannic acidAlloyCorrosionCorrosion inhibitorMetallurgyMaterials scienceChemistryChemical engineeringOrganic chemistryEngineeringCorrosion Behavior and InhibitionConcrete Corrosion and DurabilityHydrogen embrittlement and corrosion behaviors in metals