Chongliang Cui

Microstructure and tensile properties of Mg–Li–Al–Zn based alloys with Ce addition

Abstract Mg-5Li-3Al-2Zn-xCe (x=0–2.5; mass fraction, %) alloys were prepared by casting, and heat treatments of homogenization at 300 °C and solid solution at 370 °C were carried out. The microstructure and tensile properties of as-cast alloys and their evolutions after solid solution were investigated. The results show that with the increase of Ce content, Al2Ce/Al3Ce precipitates are formed and the alloys mainly consist of α-Mg, Al2Ce, Al3Ce and AlLi phases, and the amount of AlLi and Al-Ce intermetallics decreases after solid solution. The content and morphology of the second phases have important effects on the mechanical properties of the alloys; the alloy with 1.0%Ce content exhibits excellent tensile strength. The tensile strength and elongation of Mg-5Li-3Al-2Zn-0.5Ce alloy is remarkably improved by the solution strengthening effect because of the addition of Ce.

Influence of Nd and Y on texture of as-extruded Mg–5Li–3Al–2Zn alloy

Mg–5Li–3Al–2Zn alloys with the additions of Y and Nd were prepared using induction melting furnace under the atmosphere of pure argon; then they were extruded. The textures of the as-extruded alloys were analyzed by pole figures and electron backscatter diffraction. Results show that the addition of a small amount of Nd can weaken the basal texture. The further increase of Nd content has no corresponding further influence on texture. When a small amount of Y is used to replace Nd, the basal texture can be further weakened and the prismatic slip system can be further activated. In the alloy of Mg–5Li–3Al–2Zn–1.2Y–0.8Nd, the basal textures almost vanish.

Microstructure and texture evolution of Mg–Li alloy during rolling

Abstract This paper investigates the microstructure and texture evolution of as-rolled Mg-5Li-3Al-2Zn-1.2Y-0.8Nd. During rolling (both warm rolling and hot rolling), many twins appear in the alloy, some of which are cross-twins. Dynamic recrystallization occurs, resulting in grain refinement. With the increase of rolling reduction percentage, basal texture appears, and then finally non-basal texture appears. The non-basal texture during warm rolling begins to appear under a smaller rolling reduction percentage than that during hot rolling. When the rolling reduction is 28 %, the angles between the majority of c-axes and rolling direction are mainly about 25°. When the rolling reduction percentage is 52 %, the textures are strengthened.

Solid-state composite technology for B4Cp reinforced magnesium-lithium alloy

B4C(subscript p)/Mg-8Li-1Zn and B4C(subscript p)/Mg-8Li-1Al-1Y composites were prepared with hot-extrusion solid-state composite processing. The microstructures and mechanical properties of the composites were studied. With the optimized parameters, the deformation effects and the migration of α phase are improved, and the amount and size of foil gaps are decreased. The bonding force between foils is improved, and the oxidation of foils is lowered. The results of tensile test show that the strengths of the B4C(subscript p)/Mg-8Li-1Zn and B4C(subscript p)/Mg-8Li-1Al-1Y composites are increased obviously after hot-extrusion solid-state composite processing (238 MPa and 257.23 MPa, respectively). The specific strength of B4C(subscript p)/Mg-8Li-1Al-1Y composite is the highest (169.23×10^3 cm).