Creep behaviors of Mg-5Li-3Al-(0,1)Ca alloys

Mg-Li base alloys are becoming more and more arresting because of their super-light weight property. However, the creep property of Mg-Li base alloys is somewhat poor. The addition of Ca in Mg base alloys can improve the creep property of the alloys, and it also can bring about some other advantages, such as refinement, improved recrystallization during hot forming processes. In this paper, the 0.5 wt.% and 1 wt.% of Ca were used as alloying element in Mg-5Li-3Al alloy. The creep tests of extruded Mg-5Li-3Al-0.5/1Ca alloys were carried out at different temperatures (373 K. 398 K. 423 K) and stresses (35 MPa, 55 MPa, 75 MPa). The results show that the creep mechanism of extruded Mg-5Li-3Al-0.5Ca alloy is grain boundary sliding and twinning, and that of extruded Mg-5Li-3Al-1Ca alloy is grain boundary sliding. Under test conditions, the creep resistance of extruded Mg-5Li-3Al-0.5Ca is higher than extruded mg-5Li-3Al-1ca. (C) 2011 Elsevier Ltd. All rights reserved.