Inhibitive effect of sodium molybdate on corrosion behaviour of AA6061 aluminium alloy in simulated concrete pore solutions

Corrosion inhibition of MoO42 for AA6061 aluminium alloy in simulated concrete pore solutions was investigated. Electrochemical methods were adopted to assess corrosion behaviour of AA6061 and surface characterizations were employed to obtain composition and morphology of oxide layers. Results show that low concentration (6 mM) of MoO42 cannot inhibit corrosion, while MoO42 of 10-30 mM effectively inhibits corrosion, which obeys Langmuir adsorption isotherm. MoO42 acts as an anodic inhibitor. 10 mM MoO42 exhibits an optimum corrosion inhibition efficiency. A uniform oxide layer consisting of Al-Ca-Mo(V)-O(H) complexes forms in moderate concentration of MoO42 (10 mM). Inhomogeneous oxide layer consisting of Al-Mg-Si-O(H) and Al-Ca-Mo(VI)-O(H) complexes forms in high concentration of MoO42 (30 mM). (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The corrosion inhibition of MoO42 for AA6061 aluminum alloy in simulated concrete pore solutions was studied. Low concentration (6 mM) of MoO42 was ineffective in inhibiting corrosion, while concentrations of 10-30 mM were effective, following Langmuir adsorption isotherm. MoO42 acts as an anodic inhibitor, with 10 mM showing the optimum corrosion inhibition efficiency. The formation of uniform and inhomogeneous oxide layers was observed at different concentrations of MoO42.