Microstructure and mechanical properties of as-cast and extruded Mg-8Li-3Al-0.7Si alloy

Abstract

Mg-8Li-3Al-0.7Si alloy was prepared by casting and deformed by hot extrusion in this study. And the microstructure of as-cast and extruded specimens was analyzed with OM, XRD, SEM and EDS. Results show that the specimens are composed of α-Mg, β-Li, AlLi, MgLiAl₂ and Mg₂Si phases. In as-extruded specimen, the microstructure is refined and the β-Li phase has the effect of coordination during deformation. After hot extrusion, Chinese script Mg₂Si phase is crushed into block-like and distributes uniformly in the matrix. Mechanical properties results show that the strength and elongation are both improved after hot extrusion.

Keywords

Mg-Li alloy / microstructure / mechanical properties / extrusion / silicon

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