Aqueous molybdate provides effective corrosion inhibition of WE43 magnesium alloy in sodium chloride solutions

Corrosion and corrosion inhibition of WE43 magnesium alloy were investigated in NaCl solutions containing different amounts of sodium molybdate. Electrochemical, microscopic, and spectroscopic experiments were utilized to examine the mechanism of corrosion inhibition by molybdates. Electrochemical data showed that Na2MoO4 inhibitor provides reliable inhibition at concentrations at and above 100 mM. Raman and XPS spectroscopy demonstrated that the formed surface layer consists of mixed Mo(V, IV) species. This layer provided inhibition with an efficiency of 91-99 % after 24 h of exposure. A two-step oxidation-reduction mechanism of corrosion inhibition of the WE43 alloy by aqueous molybdates was proposed.

Automated summary

The study showed that the Na2MoO4 inhibitor can provide reliable corrosion inhibition for WE43 magnesium alloy at concentrations of 100 mM and above, with the formed surface layer consisting of mixed Mo(V, IV) species that exhibit an inhibition efficiency of 91-99% after 24 hours of exposure. A two-step oxidation-reduction mechanism of corrosion inhibition of the WE43 alloy by aqueous molybdates was proposed.