The Zn²⁺ Destabilized Surface Film and Accelerated Corrosion of Magnesium

Abstract

The effect of Zn2+ ions on the corrosion of pure magnesium (Mg) in NaCl solutions was systematically investigated by means of hydrogen evolution, weight loss, surface analysis, polarization curve and solution pH measurements. It was found that the presence of Zn2+ ions in the solution could significantly accelerate the dissolution of Mg. A new mechanism of surface film destabilization was proposed for the detrimental effect of Zn2+ on Mg corrosion, aiming to provide insight into the corrosion behavior of Zn-containing Mg alloys and the galvanic corrosion of Mg alloys coupled by Zn alloys.

Corrosion Behavior and Biocompatibility of Diamond-like Carbon-Coated Zinc: An In Vitro Study

“… 35 , 36 Hence, it is believed that galvanic corrosion happened between the DLC films and Zn substrate. 37 In this system, the Zn substrate is the anode and the DLC film is the cathode. At the anode, Zn loses electrons to form Zn 2+ , and at the cathode, H + from H 2 PO 4 – and HPO 4 2– reacts with electrons to form H 2 .…”

“…Furthermore, the DLC film is a kind of carbon-based material with a typical amorphous microstructure and includes both sp 3 (diamond-like) and sp 2 (graphite-like) bonds. The existence of sp 2 bonds endows DLC coating with relatively good electrical conductivity. , Hence, it is believed that galvanic corrosion happened between the DLC films and Zn substrate . In this system, the Zn substrate is the anode and the DLC film is the cathode.…”