Texture Modification and Ductility Enhancement in Mg Alloy Through Friction Stir Processing

The effects of friction stir processing (FSP) parameters, i.e., rotation and travel rates of the processing tool, on the texture modification and ductility enhancement of an Mg alloy AZ31B were investigated. With the systematic change in processing parameters as a function of the Zener-Hollomon parameter, a transition of different crystallographic texture was observed through neutron diffraction measurement, which correlated well with the changes in deformation and recrystallization mechanism activated during the processing. The variation in the texture leads to dramatic changes in the strength and ductility in the stir zone of the processed Mg plate. A maximum of three-fold increase in the ductility was achieved in the Mg alloy through FSP when the Zener-Hollomon parameter exceeds 1012 s−1 which is associated with low rotation speed and high travel speed processing conditions.