| Title |
Effect of Aging Heat Treatment on the Electromagnetic Shielding Effectiveness of AZ61 Alloy Sheets |
| Authors |
김경택(Kyeng-Taek Kim) ; 김성제(Seong-Je Kim) ; 강민혁(Min-Hyeok Kang) ; 이상봉(Sangbong Yi) |
| DOI |
https://doi.org/10.3365/KJMM.2026.64.6.564 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Mg Alloy; Secondary phase; Aging heat treatment; Microstructure; Electromagnetic wave |
| Abstract |
With the rapid advancement of information technology, the use of advanced electronics comprised
of high density integrated circuits has become indispensable in various application fields, such as unmanned
aerial vehicles and autonomous driving. Mutual interference among internal components can reduce
electromagnetic compatibility and degrade signal quality. Thus, lightweight materials with excellent
electromagnetic shielding properties and durability are required, particularly, for application into electronic
devices. In this study, we have investigated the improvement of electromagnetic shielding effectiveness of
lightweight magnesium alloys via aging treatments. Formation and growth of secondary phases, were
analyzed during the aging treatment of AZ61 magnesium alloy sheets at 200 °C for 1 h, 35 h, 184 h, 250 h,
and 300 h. The correlation among microstructural evolution, electrical conductivity, and electromagnetic
shielding effectiveness was examined. EBSD, XRD, and EDX analyses revealed that the amount of Mg17Al12
precipitates gradually increased with aging time. In the range of low-frequency, the as-rolled specimen with
high dislocation density and deformation energy exhibits the highest shielding effectiveness due to enhanced
scattering of incident electromagnetic wave. In contrast, in the high-frequency region, the specimens aged for
250 h and 300 h showed superior shielding performance as the increased amount and size of precipitates and
accompanying interfaces to matrix promotes electromagnetic wave reflection. The electrical conductivity
decreases after the solution treatment attributed to lattice distortion by solute atoms. It increases again as
the amount of the solute atoms decreases with formation of precipitates. The AZ61 specimen aged for 250
h exhibited the highest shielding effectiveness due to the balanced combination of homogeneously distributed
precipitates and electrical conductivity. This study demonstrates that the electromagnetic shielding behavior
of magnesium alloys is strongly dependent on microstructural evolution during aging, confirming that the
AZ61 alloy has high potential as a lightweight and high-performance electromagnetic shielding material. |