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With the lightest green structural material for 21st century, a significant weight reduction effect was expected to solve the lightweight problem in aerospace and other fields. However, the material's poor mechanical properties and flammability limited its widely application in such fields. In this paper, the GWK series alloys (Mg-5.3Gd-4.11Y-0.13Zr, Mg-5.5Gd-4.22Y-0.19Zr, and Mg-5.46Gd-4.02Y-0.20Zr, in wt.%) were designed, and we explored the effect of alloy composition and process on the microstructure and properties of GWK series alloys subject to casting, homogenization, extrusion, ageing and ignition. The result show that Mg-5.3Gd-4.11Y-0.13Zr alloy after T4 treatment at 500 °C/6 h obtains an excellent solid solution effect. In addition, the aged alloy shows a good balance of mechanical properties, a tensile strength of 405 MPa, yield strength of 275 MPa, as well as elongation of 8.12%, and excellent non-flammability. [ABSTRACT FROM AUTHOR]

High thermal conductivity, high strength and non-flammability have successfully been achieved concurrently for the first time in Mg-4.5Al-2.5Ca, Mg-5Al-3Ca, Mg-6Al-4Ca, and Mg-4Al-2Ca-0.03Be (at%) alloys, which are produced by hot extrusion of the heat-treated cast alloys. These alloys consist of α-Mg, and C36, C14 and C15 compounds, and exhibit a high thermal conductivity of 111-119Wm-1K-1, a high ignition temperature of 1343-1408K and a high tensile yield strength of 318-363 MPa. [ABSTRACT FROM AUTHOR]

With the lightest green structural material for 21st century, a significant weight reduction effect was expected to solve the lightweight problem in aerospace and other fields. However, the material’s poor mechanical properties and flammability limited its widely application in such fields. In this paper, the GWK series alloys (Mg-5.3Gd-4.11Y-0.13Zr, Mg-5.5Gd-4.22Y-0.19Zr, and Mg-5.46Gd-4.02Y-0.20Zr, in wt.%) were designed, and we explored the effect of alloy composition and process on the microstructure and properties of GWK series alloys subject to casting, homogenization, extrusion, ageing and ignition. The result show that Mg-5.3Gd-4.11Y-0.13Zr alloy after T4 treatment at 500 °C/6 h obtains an excellent solid solution effect. In addition, the aged alloy shows a good balance of mechanical properties, a tensile strength of 405 MPa, yield strength of 275 MPa, as well as elongation of 8.12%, and excellent non-flammability.

A new Mg alloy with the composition of Mg-8Al-0.3Zn-0.1Mn-0.3Ca-0.2Y was successfully fabricated by a low-temperature, low-speed indirect extrusion process. The extruded alloy showed excellent mechanical properties, i.e., a tensile yield strength of 379.3 MPa, ultimate tensile strength of 421.7 MPa, elongation of 11.3%, and yield asymmetry of 0.95, as well as a very high chip ignition temperature of 820 °C. The outstanding mechanical properties are attributed to the microstructural characteristics of the extruded alloy, that is, (i) grain boundary strengthening by fine recrystallized grains, (ii) precipitation hardening by abundant fine Mg 17 Al 12 precipitates, and (iii) strain hardening by the deformed non-recrystallized region with a strong basal texture that is unfavorable for basal slip during tension. Electron backscatter diffraction results showed that no twinning occurred in the recrystallized grains, which had a very small size of approximately 800 nm, whereas {10–12} twins were formed in the non-recrystallized grains even at low compressive stress, which consequently increased the yield asymmetry. [ABSTRACT FROM AUTHOR]