In Situ Atomic-Scale Oscillation Sublimation of Magnesium under CO₂ Conditions

Abstract

Understanding the interactive role between Mg and CO 2 is crucial for many technological applications, including CO2 storage, melting protection, corrosion resistance and ceramic welding. Here we report observations of rapid oscillation sublimation of Mg at room temperature in the presence of both CO 2 gas and electron irradiation using environmental transmission electron microscopy. The sublimation is mainly related to phase transformation of amorphous MgCO 3. Differing from the direct formation of gas-state MgCO3 which attributes to the sublimation of pure Mg under a mild electron beam dose, a unique oscillation process is detected during the process of Mg sublimation under a harsh electron beam dose. The main reason stems from the first-order reaction of a reversible decomposition-formation of amorphous MgCO 3. These atomic-level results provide some interesting insights into the interactive role between Mg and CO 2 under electron beam irradiation.

A new environmentally-friendly route to in situ form a high-corrosion-resistant nesquehonite film on pure magnesium

“…Recently, the carbonation method has emerged an attractive and promising method for the corrosion protection of Mg metal. 2,7,8 Through reaction with the CO 2 excited by either a high-energy electron beam or a glow discharge, Wang et al 2,7 carbonated an Mg-based material to create a smooth and dense magnesium carbonate protective lm. The inhibition effects of this protective lm are superior to those of the anodized coating, and the inhibition performance can be even be as good as that of a micro-arc oxidation coating.…”

“…The inhibition effects of this protective lm are superior to those of the anodized coating, and the inhibition performance can be even be as good as that of a micro-arc oxidation coating. Sun et al 8 also investigated the interaction between excited CO 2 and Mg substrate under electron beam irradiation and observed a rapid and unique oscillation sublimation process of the Mg metal at room temperature. However, to date, this carbonation method applied to Mg-based materials must rely on activation by either a high-energy electron beam or a glow discharge.…”