The effect of rare earth elements on the behaviour of magnesium-based alloys: Part 1-Hot deformation behaviour

The hot deformation behaviour of two magnesium alloys, AZ31 and Mg-1.5Gd, have been examined in order to study the effect of the rare earth element Gd on the hot deformation behaviour. The as-cast alloys dynamically recrystallised during deformation, but retained a large amount of as-deformed microstructure. The hot deformed microstructures were examined with EBSD and TEM. The Mg-Gd alloy was found to produce a more refined substructure and develop larger average misorientations within the as-deformed grains compared to AZ31. From these observations it is inferred that Mg-Gd develops a higher stored energy than AZ31 during deformation, and that dynamic restoration is more inhibited in the Mg-Gd alloy. (C) 2012 Elsevier B.V. All rights reserved.