Effect of Al addition on the elevated temperature deformation behavior of Mg-Zn-Y alloy

The effect of the addition of Al on the high temperature deformation behavior of wrought Mg-4Zn-0.8Y alloy has been investigated. The addition of Al significantly improves the high temperature formability, i.e. increases elongation from 260% to 370% under a strain rate of 1 x 10(-4) s(-1) at 300 degrees C. Strain rate sensitivity measured at different strain rates shows that the addition of Al induces the transition of high temperature deformation mechanism from dislocation creep mode to grain boundary sliding mode. Effect of alloying elements and microstructural evolution including the role of icosahedral-phase during deformation are discussed. (c) 2007 Elsevier B.V. All rights reserved.