Microstructure and mechanical properties of Mg-xLi-3Al-1Ce alloys
(Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education,
Harbin Engineering University, Harbin 150001, China)
Harbin Engineering University, Harbin 150001, China)
Abstract: Several Mg-xLi-3Al-1Ce alloys were prepared by vacuum induction heating. These alloys are Mg-5Li-3Al-1Ce, Mg-8Li-3Al-1Ce and Mg-14Li-3Al-1Ce, respectively. The microstructure and phase composition of these alloys were analyzed by optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffractometry. The mechanical properties of these alloys were measured with tensile tester. The results show that, Mg-5Li-3Al-1Ce has a single phase (α) structure, Mg-8Li-3Al-1Ce has a double phases (α+β) structure, Mg-14Li-3Al-1Ce has a single phase (β) structure. And some compounds distribute in the matrix. After being rolled, the grain size of all the alloys is refined. Under the condition of the same content of other alloying elements, the mechanical properties of Mg-5Li-3Al-1Ce are relatively high. With increasing Li content, the strength of both as-cast and as-rolled alloy decrease. For the as-cast alloys, with increasing Li content, the elongation increases. While for the as-rolled alloys, with increasing Li content, the elongation decreases. Ce has refining effect on these alloys.
Key words: Mg-Li alloy; microstructure; mechanical properties