Optimizing microstructure for enhanced performance: A novel approach to EMI shielding with thin Mg98.5Zn0.5Y alloy sheets

Abstract

The growing demand for lightweight, high-performance, cost-efficient electro-magnetic interference (EMI) shielding materials, driven by advancements in 5G telecommunications, electric vehicles, and wearable electronics, has prompted the development of a 0.8 mm Mg_98.5Zn_0.5Y alloy sheet with a unique lamellar structure. Fabricated via asymmetrical warm rolling, this alloy demonstrated outstanding EMI shielding effectiveness (SE) of 100–105 dB across the 30–1500 MHz range, outperforming other materials and thicker magnesium alloys. The superior EMI shielding performance is attributed to the interface between the α-Mg matrix and 14H-LPSO phases with contrasting conductivities, enhancing electromagnetic wave reflection and propagation within the shielding system. Additionally, increased rolling passes lead to higher density of 14H-LPSO phases and reduced lamellar spacing, contributing to improved internal reflection and energy dissipation. This work suggests that the lightweight and ultra-thin Mg_98.5Zn_0.5Y sheet, with its optimized microstructure, holds great potential as a high-performance EMI shielding material for practical electronic applications.