Fine-grained magnesium alloy QE22 (Mg-2.5wt.% Ag-2.5wt.% RE-0.6wt.% Zr) was prepared from cast ingot which was submitted to a two stages heat treatment. Subsequently the billet was overaged and extruded at high temperature.
Samples were deformed at elevated temperatures from 380 degrees C up to 480 degrees C at various strain rates. Microstructure of deformed samples was studied using light and electron microscopy.
Conditions for superplasticity of the investigated alloys have been estimated. Possible deformation mechanisms are discussed.