Mechanical Properties Of As-extruded Alloys Research Articles

Effects of Al on microstructure and mechanical properties of hot-extruded Mg–3Nd alloys

The effects of Al content on microstructure, texture, and mechanical properties of as-extruded Mg–3Nd alloy were investigated. The particle stimulated nucleation effect of Al2Nd and Al11Nd3 phases promotes dynamic recrystallisation and the texture is weakened of the as-extruded alloys. With the increase in Al content in the alloys, the microstructure transformed from a bimodal structure to an almost fully recrystallised structure. Grain refinement, the distribution of the second phases, and texture are important factors determining the mechanical properties of as-extruded alloys. As-extruded Mg–3Nd–3Al achieved a good balance of strength and plasticity. The ultimate tensile strength, yield strength, and elongation are 283, 221.3 MPa, and 15.7%, respectively.

Effect of the pre-homogenization on the precipitation behaviors, mechanical and corrosion properties of as-extruded Mg Y binary alloys

The effect and its mechanism of pre-homogenization of as-extruded MgY alloys on mechanical and corrosion properties are investigated by the tensile and compressive tests, immersion, and electrochemical tests. The pre-homogenized temperature would improve the mechanical properties of as-extruded alloys by influencing fine grain strengthening, precipitation strengthening, and solid solution strengthening. The higher Y content would accelerate the micro-galvanic effect of the second phases and the impurities to worse the corrosion resistance of the matrix. In contrast, the higher pre-homogenization reduces the micro-galvanic effect by decreasing the volume fraction. The as-extruded alloys (wt%) with pre-homogenization of 500 °C exhibit relatively excellent corrosion resistance due to the weaker micro-galvanic effect, the lower interface energy, and the strong {0002} 〈10−10〉 basal texture. Furthermore, the as-extruded Mg11Y pre-homogenizing at 500 °C performs superior mechanical properties attributing to the bimodal microstructure and the solid solution strengthening of Y

Microstructure, texture, and mechanical properties of as-extruded Mg-xLi-3Al-2Zn-0.2Zr alloys (x = 5, 7, 8, 9, 11 wt%)

The microstructure, texture, and mechanical properties of as-extruded Mg-xLi-3Al-2Zn-0.2Zr alloys (x = 5, 7, 8, 9, 11 wt%) were investigated. After hot extrusion, the filamentous AlLi phase in α-Mg is crushed into tiny particles, while the morphology of round-like AlLi phase in β-Li remains unchanged. The threadlike MgLi2Al phase precipitated during hot extrusion only distributes along the grain boundaries of β-Li phase. The grains of as-extruded alloys are refined markedly due to dynamic recrystallization (DRX), and α-Mg phase undergoes discontinuous DRX while β-Li phase undergoes continuous DRX. The {0001} basal, {101¯0} and {112¯0} prismatic fiber textures formed in α-Mg phase suggest the activation of both basal and prismatic slip, and the intensity of prismatic texture is higher than that of basal texture. In β-Li phase, as the extrusion temperature increases and the Li content decreases, the intensities of α fiber and {110}110 textures decrease while those of γ fiber and {110}//ED textures increase. Compared with as-homogenized alloys, the mechanical properties of as-extruded alloys are significantly improved owing to grain refinement strengthening, texture hardening, strain hardening, and second phase strengthening.

Microstructure and mechanical properties of Mg–6Li–xAl–0.8Sn alloys

ABSTRACTAs-cast and as-extruded Mg–6Li–xAl–0.8Sn (x = 0, 1, 3 and 5 wt-%) alloys were prepared. The microstructure and mechanical properties were investigated and discussed. The experimental results show that the Mg–6Li–0.8Sn alloy is composed of three phases: α-Mg, Mg2Sn and Li2MgSn. With the addition of Al, the test alloys display typical α-Mg + β-Li duplex structures. The new Mg17Al12 and LiMgAl2 phases were found in the Mg–6Li–1Al–0.8Sn alloy. The lamellar-type AlLi phase was formed whereas the Mg17Al12 phase disappeared in Mg–6Li–3Al–0.8Sn alloy. The LiMgAl2 phase vanished in the Mg–6Li–5Al–0.8Sn alloy. The mechanical properties of as-extruded alloys were remarkably improved. The as-extruded Mg–6Li–3Al–0.8Sn alloy exhibited the best mechanical properties, with a yield strength, tensile strength and elongation of 209.8 MPa, 242.6 MPa and 15.5%, respectively.

Effect of Extrusion Temperatures on Microstructures and Mechanical Properties of Mg-3Zn-0.2Ca-0.5Y Alloy

After solution treatment, the Mg-3Zn-0.2Ca-0.5Y alloy was subjected to extrusion at various temperatures and extrusion defects, microstructures and mechanical properties of as-extruded samples were studied in detail. The results show the extrusion temperature has a slight effect on DRXed grain size due to the presence of Y-containing phase with a good thermal-stability. On the contrary, the mechanical properties of as-extruded alloys are remarkably influenced by dynamic recrystallization degrees promoted by extrusion temperatures. A good formability of as-extruded bars with an optimal mechanical properties and fine-grained microstructure was obtained by extrusion at 250°C and the mechanical performances are significantly superior to those of hot-rolled ZK60 obtained at the same temperature. In this paper, the magnesium alloy with fine-grained (<5μm), high ductility (>30%) and high strength (>250MPa) was fabricated easily by a simple extrusion process.