Historical progress in electromagnetic interference shielding effectiveness of conventional Mg alloys leading to Mg-Li-based alloys. A review

Magnesium alloy (Mg alloy) materials have attracted considerable attention recently due to their potential applications in electronics, communication, computers, aerospace, and defense regarding electromagnetic interference (EMI) shielding, where high performance and reliability are required, and the unwanted electromagnetic fields are prevented from interfering with the regular operation of electronic devices and systems. Material's EMI shielding effectiveness (SE) depends on several factors: conductivity, magnetic permeability, reflectivity, absorption, and multiple scattering. Mg alloys also have high conductivity, magnetic permeability, high stiffness, high specific strength, and high damping properties. This makes them a better SE material than other shielding materials, such as Al alloys, for practical purposes. Various methods, such as alloying, heat treatment, deformation, surface treatment, and composite fabrication, can be used to modify Mg alloys to improve their SE and other properties. This review summarizes the recent progress and challenges in developing Mg alloy materials for EMI shielding applications. The effects of different factors on Mg alloys' SE, such as composition, microstructure, frequency, and thickness, are discussed. Also, the importance of Mg-Li alloys and why they are better electromagnetic shielding materials than conventional Mg alloys is discussed. Finally, some perspectives and suggestions for future research directions are provided. (© 2023 Wiley‐VCH GmbH)