There is an increasing demand for light structural alloys, particularly for transport applications and consumer products. As a result, the interest for light Mg-based materials has been increasing in recent years. Mg is the lightest structural metal (2/3 the density of aluminium and 1/4 that of steel) and it shows an outstanding specific strength.

Designation of Mg alloys is given by the American Society for Testing and Materials and consists of four digits. First two letters identify the main alloying elements (e.g. A: Aluminium, E: Rare earths, K: Zirconium, L: Lithium, M: Manganese, Q: Silver, S: Silicon, Z: Zinc. The third and fourth digits correspond to the percentages of the main alloying elements. Sometimes, a fifth digit is included at the end to indicate the generation of the alloy.

At a commercial level, alloys from the Mg-Al system are the most important ones. Al facilitates casting and provides an optimum combination of mechanical strength, hardness and corrosion resistance. However, Mg-Al alloys show poor creep performance at temperatures higher than 125 ºC. This has led to research and development of new systems for medium and high temperatures. Mg-Zn-Y and Mg-Zn-RE systems are typical examples of Al-free Mg alloys. Some of these alloys form LPSO phases (Long Period Stacking Ordered, LPSO) which significantly improve the mechanical properties of Mg.

Recent advances in Mg technology are related to the biomaterials field. Mg alloys can be used for temporary implants. Stents and orthopedic implants are examples of potential applications for Mg alloys. The ultimate goal is to avoid a second surgery for implant removal. Mg alloys for implant applications contain bioactive elements such as Ca and Zn, which are essential for the human body.

This section includes commercial alloys which are typically used for the transport sector. 

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