Synthesis and characterization of Al–Mg–Zn thin film alloys co‐deposited from vapour phase

Abstract

732 2468 8905 Web: www.jku.at/ictas Mg-Zn thin film alloys were produced by thermal co-evaporation using single source and dual source geometries. The films containing high amount of Zn (66 at.%) were prone to formation of metallic micro spheres on the surface when high evaporation rates (10 nm s À1 ) were used. The Mg-27.1 at.% Zn bulk alloy was found to be suitable for co-deposition with Al for producing Al-Mg-Zn thin film alloys. A low Al concentration gradient (5 at.%) could be obtained along the sample due to the high deposition rates of Mg-Zn (7.5 nm s À1 ) combined with low Al deposition rates (0.2 nm s À1 ). The Al-Mg-Zn thin films showed an improved resistance against chemical attack when higher amounts of Al are used, as shown by downstream analytics investigations using a flat flow electrochemical cell coupled to an AAS system.

Self-Healing Phenomenon at the Cut Edge of Zn-Al-Mg Alloy Coated Steel in Chloride Environments

“…The occurrence of corrosion defects was mainly attributed to anodic dissolution, inducing the generation of hydroxide ions as electrons are transferred to the cathodic region. The resulting pH difference can significantly influence the corrosion process, where an increase in pH can lead to the formation of corrosion products [30]. In an alkaline environment with high pH, Mg(OH) 2 is reported to remain stable as it does not undergo further chemical reactions [31], but in chloride environments, Mg(OH) 2 can continue to corrode, forming MgCl 2 along with Mg 2 (OH) 3 Cl.…”

Film dissolution kinetics of aluminium at precisely adjusted pH‐values

“…Aluminium is used in many different fields like nuclear reactors, aerospace, automotive, construction, aluminium alloys, coatings and metal/air batteries . At neutral pH values, a thick oxide film is formed, which acts as barrier layer .…”