Clarifying the Dissolution Mechanisms and Electrochemistry of Mg2Si as a Function of Solution pH

The dissolution kinetics of magnesium silicide (Mg2Si) were investigated herein. The rationalization of Mg2Si electrochemistry is relevant in the context of several commercial aluminum alloys, magnesium alloys, and magnesium containing galvanising. The dissolution rates of Mg and Si were quantitatively measured, as a function of solution pH, using atomic emission spectroelectrochemistry (AESEC), providing previously unreported insights into the corrosion mechanism of Mg2Si. Results revealed pH dependent dissolution of Mg and Si, in addition to the prominent role of Si in the passivation of Mg2Si in slightly alkaline pH (8). (C) The Author(s) 2018. Published by ECS.