Study on edge cracking and texture evolution during 150°C rolling of magnesium alloys: The effects of axial ratio and grain size

Pure Mg, AZ31 (Mg-3 wt%Al-1 wt%Zn) and experimental alloys, Mg-1 wt%Zn-1 wt%In, Mg-2 wt%Li-1 wt%Zn, Mg-2 wt%Li-1 wt%Zn-1 wt%In were rolled at 150 degrees C to 0.3 and 0.55 strain. The samples rolled to 0.3 strain were subsequently annealed for 10 min at 400 degrees C. The texture was evaluated in rolled and in rolled/annealed conditions. The axial ratio (c/a) of the alloys strongly influenced edge cracking during rolling (expressed as cracking index, I(C)), which was explained via the influence of c/a on the twinning mode. The as-cast grain size did not correlate to I(C) (edge cracking). Texture intensity was strongly influenced by the as-cast grain size (which was attributed to plastic compatibility at grain boundaries), showed weak correlation to the lattice parameter a, but did not depend on c/a. The Mg-2 wt%Li-1 wt%Zn alloy, with fine grain size and small c/a and a, exhibited the optimum combination of weak texture and crack-free rolling at 150 degrees C. (C) 2011 Elsevier B.V. All rights reserved.