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Microstructure, electromagnetic shielding effectiveness (SE), and mechanical properties of Mg-12Gd-3Y-xSn alloys were systematically studied to understand the effect of Sn addition on the structure and properties of the alloy. The experimental results show that the number of second phases increases after adding Sn, and Mg24(Gd, Y)5, Mg5(Gd, Y), and Mg2Sn phases are formed. The SE values of Mg-12Gd-3Y-xSn alloys increase gradually with the addition of Sn. Mg-12Gd-3Y-1.5Sn alloy subjected to artificial aging at 225°C for 36 h presents the SE value of 113-81 dB and a maximum increment in SE of 11 dB at 1500 MHz. The ultimate tensile strength of the aged Mg-12Gd-3Y-1.5Sn alloy at 250 °C can reach 345 MPa. When the incident direction of the electromagnetic wave is perpendicular to the basal plane, the Mg2Sn phase precipitated parallel to the (0001)α-Mg plane has more reflection area, which increases the SE value. The improved SE value is mainly due to the enhanced multiple reflection attenuations by the second phase. The precipitates β' and Mg2Sn have high-temperature stability, making the alloy still exhibit good mechanical properties at 250 °C. [ABSTRACT FROM AUTHOR]

In recent years, a great demand exists for Mg alloy materials that combine excellent mechanical properties and electromagnetic interference shielding effectiveness (EMI SE). In this study, the effects of La content on the microstructure, mechanical properties, and EMI SE of Mg-6Zn-1Y-xLa-0.5Zr alloys are reported in detail. The microstructures of Mg-6Zn-1Y-xLa-0.5Zr alloys treated by extrusion all exhibit bimodal microstructure characteristics. Mg-6Zn-1Y-1.0La-0.5Zr alloys show a superior balance between mechanical properties and EMI SE. The UTS, YS, and elongation were 332.3 MPa, 267.3 MPa, and 16.2 %, respectively. Meanwhile, the EMI SE in the frequency range of 30–1500 MHz is 79–110 dB, and the excellent mechanical properties are due to the combined effect of fine-grain strengthening, second-phase strengthening, and heterogeneous structure strengthening. The excellent EMI SE is mainly attributed to the dense and diffusely distributed second phase providing more interfaces that can reflect electromagnetic waves. • The Mg-6Zn-1Y-xLa-0.5Zr alloys in the extruded state exhibited similar bimodal microstructural features. • The Mg‐6Zn‐1Y‐1La‐0.5Zr alloy in the extruded state achieved the highest strength without a significant decrease in elongation. • The enhancement of the EMI SE is attributed to the increase in La content, which resulted in the creation of more second phases within the alloy. [ABSTRACT FROM AUTHOR]

Electromagnetic waves generated by electronic equipment are widely present in all living and working spaces because of the rapid development of electronic products and frequent use of digital systems. Electromagnetic shielding is an effective method of protection against these waves. Therefore, the demand for materials with high electromagnetic shielding properties has remarkably increased. Magnesium (Mg) alloys, as potential electromagnetic shielding materials, have sparked great interest worldwide. This review highlights the effects of grain size, texture, alloying elements and second phase on the shielding properties of Mg alloys. Recent progress on the shielding properties of Mg–Zn, Mg–Al, Mg–RE and other new shielding Mg alloys is then summarised, and the successful design of Mg alloys with superior electromagnetic shielding properties, such as Mg–Zn–Y–Ce–Zr, Mg–Sn–Zn–Ca–Ce, Mg–Gd–Y–Zn–Zr and Mg-based composite materials, is described. Finally, this review provides insights into the future development and applications of Mg alloys with superior shielding properties. [ABSTRACT FROM AUTHOR]

The strength and electromagnetic shielding capability are two essential requirements for lightweight metallic materials as shielding materials. However, it is still a challenge to develop magnesium (Mg) alloys with both high strength and favorable electromagnetic shielding capability. Herein, the results show that alloying with Sn in Mg–xSn–Zn–Ca–Ce alloys simultaneously increases both strength and electromagnetic shielding effectiveness (SE). After Sn alloying, the average grain size of the alloys is greatly reduced, whereas the intensity of basal texture is enhanced, and the precipitation of Mg2Sn phase is promoted. The Mg–3Sn–Zn–Ca–Ce alloy attains best comprehensive mechanical properties and electromagnetic SE (ultimate tensile strength (UTS) of 337 MPa and SE of 91–114 dB) in Sn containing alloys. The increase in strength is attributed to the combination of grain refinement, texture strengthening, and precipitation strengthening. The great electromagnetic SE is mainly due to the regularly arranged Mg2Sn precipitates in the basal plane. [ABSTRACT FROM AUTHOR]

Magnesium (Mg) alloy sheets with excellent mechanical properties and electromagnetic interference shielding effectiveness (EMI SE) have great application prospects. This study investigates the microstructure, mechanical properties, and EMI SE of extruded and rolled Mg-6Zn-1Y-0.5Zr sheets. In the Mg-6Zn-1Y-0.5Zr alloy subjected to extrusion and rolling, the predominant internal second phases are Mg-Zn-Y and Mg Zn, with the volume fraction of the second phase increasing with cumulative strain. After the extrusion treatment, the average grain size of the Mg-6Zn-1Y-0.5Zr alloy was 2.7 μm. Increasing the rolling reduction to 37% resulted in an average grain size of 5.27 μm, while a rolling reduction to 75% decreased the grain size to 4.06 μm. The Mg-6Zn-1Y-0.5Zr alloys exhibited consistent trends in ultimate tensile strength (UTS), yield strength (YS), and elongation (EL) under extrusion and various rolling strain treatments. These properties showed a relationship with cumulative strain, initially increasing and then decreasing. However, the EMI SE of the Mg-6Zn-1Y-0.5Zr alloy exhibited a positive correlation with cumulative strain. The sheets obtained through a combination of extrusion plus 37% rolling treatment exhibited excellent mechanical properties and EMI SE. The Mg-6Zn-1Y-0.5Zr alloy demonstrated UTS, YS, and EL values of 331.4 MPa, 251.3 MPa, and 18.7%, respectively. The EMI SE in the frequency range of 30–1500 MHz ranged from 79 dB to 113 dB, satisfying the requirements of the electronic information field regarding the mechanical properties and EMI SE of Mg alloy sheets. • Extrusion plus rolling can significantly enhance the mechanical properties and electromagnetic interference shielding effectiveness of Mg-6Zn-1Y-0.5Zr alloys. • Dislocation strengthening is the primary hardening mode of extruded Mg-6Zn-1Y-0.5Zr alloys during the rolling process. • The comprehensive performance of the sheets obtained by extrusion plus 37% rolling treatment meets the mechanical properties and EMI SE requirements of Mg alloy sheets in the electronic information field. [ABSTRACT FROM AUTHOR]

Microstructure and electromagnetic interference shielding properties of extruded Mg-Zn-Ce-Y-Zr alloys were systematically investigated. A bimodal grain structure of fine recrystallized grains and deformed grains was observed in the alloys. Yttrium (Y) and cerium (Ce) refined the recrystallized grains. Mg-Zn-Ce phase, Mg3Zn3Y2 phase and a few precipitates containing Zn and Zr were observed. Y and Ce additions changed the texture of the alloys. When the total rare earth content reached 4 wt.%, the texture was remarkably weaker than other studied alloys. The shielding capacity increased first and then decreased with Y contents. The value of shielding effectiveness for the extruded Mg-5Zn-1Ce-2Y-0.6Zr alloys reached 79-118 dB in the frequency range of 30 MHz-1.5 GHz, which was significantly higher than that of some aluminum alloys. The addition of Y and Ce is effective in improving the shielding capacity in Mg alloys. The electrical conductivity and second phases in the alloys were important in enhancing shielding effectiveness. The texture and precipitation exerted significant effect on electrical conductivity. In addition, subsequently aging treatment evidently improved shielding effectiveness. [ABSTRACT FROM AUTHOR]

The electromagnetic interference (EMI) shielding of Sm-containing magnesium alloys in the 30-1500 MHz testing frequency range was investigated by coaxial cable method. The results demonstrated that Mg-3Zn alloys displayed the best electromagnetic shielding property. When 0.5 wt% of Zr was added for crystal grain refinement, the shielding effectiveness (SE) was apparently reduced. The addition of the rare earth element Sm in ZK magnesium alloys can improve the electromagnetic interference shielding of magnesium alloys. The main reason for the differences in electromagnetic interference shielding of magnesium alloys was the change in conductivity. The addition of Zr in Mg-Zn alloys can refine the grains and consequently improve the grain boundary area significantly. Therefore, the number of irregularly arranged atoms at the grain boundaries increased, decreasing the conductivity of magnesium alloys and leading to a decrease in the electromagnetic interference shielding. Following the Sm addition, the Mg-Zn-Sm phase was precipitated at the grain boundaries and in cores. The precipitation of Sm-containing rare earth phases could consume the solid-soluted Zn atoms within the Mg, resulting in an increase in electrical conductivity and electromagnetic interference shielding improvement. [ABSTRACT FROM AUTHOR]

The microstructure, dynamic recrystallization, texture, anisotropic behaviour, mechanical properties and electromagnetic shielding effectiveness of Mg–Zn–Zr–Ce alloys were comprehensively investigated in this study. Results indicated that the addition of Ce refined the grains and induced the formation of a Mg–Zn–Ce phase with a unique orthorhombic structure. Dynamic recrystallization was improved when Ce was added because the particle stimulated nucleation mechanism. The random orientation of recrystallization grains weakened the basal texture. The anisotropy index decreased from 1.02 to 0.43 after 1.16 wt% Ce was added. Ce addition enhanced the mechanical properties when the Ce content ranged from 0 to 1.90 wt%, and then decreased with a higher 2.74 wt% Ce content. Electromagnetic shielding effectiveness was also improved initially with the addition of Ce, and then decreased, but was still higher compared with the Ce-free alloy. Good mechanical properties and excellent electromagnetic shielding properties were simultaneously achieved through 1.16 wt% Ce addition. The alloy not only exhibited good yield strength (249 MPa), ultimate tensile strength (316 MPa), and elongation (δ=15%) but also superior electromagnetic shielding effectiveness with 71 dB at 1200 MHz. [ABSTRACT FROM AUTHOR]

The microstructure, electromagnetic interference (EMI) shielding effectiveness (SE) and mechanical properties of Mg–Zn– x Cu–Zr alloys ( x = 0–2.32 wt.%) were investigated in this study. The results indicated that the addition of Cu led to the formation of MgZnCu phase with a face-center cubic structure, and resulted in grain refinement. EMI SE increased significantly with increasing Cu content in extruded state. The alloy with 2.32 wt.% Cu exhibited optimal EMI shielding capacity with SE value of 84–117 dB. Meanwhile, it was found that good mechanical properties could be achieved by adding low Cu content. The extruded alloy with 0.37 wt.% Cu presented higher yield strength (276 MPa), ultimate tensile strength (346 MPa) and elongation ( δ = 11.4%) compared with other extruded alloys. However, a higher Cu content would substantially deteriorate tensile properties of the alloys. Based on microstructure observation, the variation of EMI shielding capacity and mechanical properties have been discussed. [ABSTRACT FROM AUTHOR]

The microstructure, electromagnetic interference (EMI) shielding effectiveness (SE) and mechanical properties of Mg–Zn–Y–Zr alloys with 0–3.91 wt.% Y were investigated systematically in this work. The results indicated that addition of Y brought about the formation of I-phase (Mg 3 Zn 6 Y) and W-phase (Mg 3 Zn 3 Y 2 ) and refined grains in as-cast state. After hot extrusion, there was more and more broken particles dispersing in matrix when Y content ranged from 0 to 3.19 wt.%. With increasing Y content, EMI SE was enhanced significantly in extruded state. The alloy with 1.9 wt.% Y exhibited the optimal EMI shielding capacity with the SE value of 79–118 dB. It was found that good mechanical properties could be achieved by adding very low Y content. The extruded alloy with 0.5 wt.% Y presented higher yield strength (268 MPa), ultimate tensile strength (334 MPa) and good elongation ( δ = 12.3%) compared with other extruded alloys. A subsequent aging treatment on the extruded alloy with 1.29 wt.% Y exhibiting outstanding comprehensive EMI SE and mechanical properties resulted in precipitation of W, β 1 ′ and β 2 ′ phases, which led to further improvement in EMI SE. The peak-aged sample showed the superior mechanical properties. Based on the microstructure observation, the changes of EMI shielding capacity and mechanical properties have been discussed. [ABSTRACT FROM AUTHOR]

Abstract: Electromagnetic interference shielding, hardness, and electrical conductivity measurements were employed to evaluate the effect of aging precipitation on shielding characteristics of ZK60 magnesium alloy. During artificial aging MgZn2 phase precipitates occurred and the age hardening peak happened at 150°C for 15h. Aging precipitation induced enhanced shielding effectiveness as well as tensile strength in the alloy. It is interesting to note that the shielding effectiveness exhibited a rapid increase with increase in aging time until 15h, but for longer aging time it tended to remain largely unchanged. Artificial aging at 150°C for 15h can thus be considered as the optimum heat treatment condition. In this condition, the good combination of superior shielding effectiveness greater than 70dB and high mechanical properties was achieved. The origin of the attractive electromagnetic interference shielding properties is discussed based on second phase precipitation in the alloy. [Copyright &y& Elsevier]

Striking a balance between the mechanical properties and electromagnetic interference shielding effectiveness (EMI SE) of Mg alloys stands as a critical concern within the realm of electronics and communications. This study endeavors to optimize the mechanical properties and EMI SE of Mg alloy sheets through a combination of extrusion and rolling (E-R). OM, SEM, XRD, EBSD, and TEM obtained the microstructures of Mg‐6Zn‐1Y‐1La‐0.5Zr alloys under extrusion and different rolling strain treatments, and the effects of the microstructures on the mechanical properties and EMI SE were revealed. The microstructure of the as-extruded Mg‐6Zn‐1Y‐1La‐0.5Zr (abbreviated as ZKL611K) alloy exhibited a distinct bimodal microstructure, with refined dynamically recrystallized (DRXed) grains surrounding coarse unDRXed regions. Subsequent rolling treatments induced a decrease in the aspect ratio of the unDRXed regions, a rapid reduction of DRXed grains, and the accumulation of dislocations within the as-rolled alloy. Statistical analysis of mechanical properties and EMI SE revealed that an optimal balance in the sheets subjected to "extrusion + 37 % rolling reduction", yield strength (YS) of 319 MPa, ultimate tensile strength (UTS) of 375 MPa, and elongation of 12.3 %. Furthermore, the EMI SE ranged from 81 dB to 114 dB within the frequency range of 30–1500 MHz. However, further increments in rolling reduction adversely affected mechanical properties while improving EMI SE. The observed enhancement in mechanical properties can be primarily attributed to the synergistic effects of grain size, second phase, dislocations, low-angle grain boundaries (LAGBs), and texture. Meanwhile, the improved EMI SE can be mainly attributed to the diffuse distribution of the second phase at multiple scales and the modulation of the texture through E-R treatments. ● The hot deformation effectively achieves a favorable balance between mechanical properties and electromagnetic shielding effectiveness in Mg‐6Zn‐1Y‐1La‐0.5Zr alloys. ● Multiple passes of rolling deformation will decrease the aspect ratio of the unDRXed regions remaining in the extruded state. ● The primary cause for the synergistic improvement in mechanical properties and electromagnetic shielding effectiveness is the influence of rolling on the second phase and the texture. [ABSTRACT FROM AUTHOR]