Passivation of corrosion product layer on AM50 Mg by corrosion inhibitor

The influence of sodium dodecyl sulfate (SDS) on morphology and chemical composition of corrosion product layer formed on alpha-Mg matrix and cathodic Al-Mn intermetallic was systematically investigated by using FIB and TEM analysis for the first time to disclose the underlying inhibition mechanism. A porous corrosion bi-layer composed of crystalline MgO and Mg(OH)2 was observed on both of alpha-Mg and Al-Mn intermetallic. It was found that a passive inner layer was deposited on alpha-Mg after immersion in SDS-containing NaCl solution, which can be ascribed to steady-state growth of magnesium and aluminum oxide under the protection of hydrophobic group of SDS. The inhibition mechanism of the inhibitor was mainly associated with formation of dense oxide layer on alpha-Mg matrix and preferential adsorption of SDS on the corrosion layer deposited on Al-Mn intermetallic.(c) 2021 Chongqing University. Publishing services provided by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/)Peer review under responsibility of Chongqing University

Automated summary

The influence of sodium dodecyl sulfate (SDS) on the formation of a corrosion product layer on alpha-Mg matrix and cathodic Al-Mn intermetallic was systematically investigated. It was found that SDS promoted the formation of a passive inner layer on alpha-Mg, leading to the steady-state growth of magnesium and aluminum oxide and inhibition of corrosion.