Microstructure, Corrosion and Mechanical Properties of Magnesium Alloys

The properties of magnesium (Mg) and its alloys such as uniquely high specific strength (strength-to-density ratio), good castability, excellent machinability, adequate high-temperature formability and high damping capacity have garnered significant interest from researchers and product designers, especially in the automotive and aerospace industries, for many years [1,2]. Although their tendency to undergo rapid corrosion due to their high electronegative potential seems to be a major drawback, these properties even confer biodegradable characteristics together with excellent biocompatibility [3,4]. As a result, magnesium alloys have become crucial materials within the biomedical industry as well. Nevertheless, there is still a need for enhancing the mechanical properties and corrosion resistance of magnesium alloys, which researchers have found difficult for years.

Currently, surface modification by coating can be regarded as the most effective approach to improve the corrosion and surface wear resistance of magnesium alloys. Various conversion or deposition techniques can be employed to create these coatings, significantly improving the surface properties of magnesium alloys [5]. However, surface coatings have minimal impact on increasing the overall material strength, and their favourable effects are confined only to a thin surface layer of the material. In addition, they require additional steps in the manufacturing process, affecting both time and cost. For this reason, optimizing the microstructure of magnesium alloys is important for achieving effective and homogenous improvements in their mechanical and corrosion resistance properties. Microstructural factors such as grain boundaries, grain orientation (texture), dislocations, solute atoms and precipitates prominently affect the properties of magnesium alloys. The most common methods for modifying microstructure include hot deformation processes such as extrusion, rolling and forging, heat treatments and alloying magnesium with various elements. Furthermore, in recent years, researchers have also directed their attention towards novel severe plastic deformation (SPD) techniques such as high-pressure torsion (HPT), equal channel angular pressing (ECAP), accumulative roll bonding (ARB), hard-plate rolling (HPR) and asymmetric cross-rolling (ACR), to produce ultra-fine grained (UFGed) magnesium alloys with an impressive combination of strength and ductility [6].

Despite all these advancements in magnesium alloys, certain properties such as corrosion resistance, high-temperature strength and wear resistance have remained low compared to those of competing materials. Consequently, there is a need to comprehend and improve the relationships between microstructure, mechanical and corrosion properties. This understanding holds paramount importance for the development of a new generation of magnesium alloys with superior performance, thereby promoting their widespread use across industries.

This Special Issue of Metals, titled “Microstructure, Corrosion and Mechanical Properties of Magnesium Alloys” aims to provide an inclusive platform by sharing the latest research breakthroughs on the properties of magnesium alloys. Original research and review articles addressing diverse topics will be considered in this Special Issue, including microstructure development, the investigation of new alloying element additions, traditional and novel thermomechanical processes, texture, mechanical properties, composites, surface modification, corrosion and corrosion protection methods.