Microstructure and Mechanical Properties of Rheo-Extruded AZ31 Mg Alloy
A new rheo-extrusion technique has been developed to produce extruded profiles. The AZ31 slurry is fabricated by a twin-screw mechanism, and has spheroidal solid particles with a grain size of about 50 to 80μm. The slurry was introduced into an extrusion container with an inner diameter of 95mm, and then squeezed to a billet before extruding into a round bar with a diameter of 22mm using a 500kN extrusion machine. It is found that the new technique has a lower deformation resistance than that of the conventionally hot extrusion technique in the same extrusion velocity. The microstructure and mechanical properties of the rheo-extruded bars were examined in detail. The results illustrated that grains of the bar were very fine with the average grain size about 2.3μm，and the mechanical properties were improved substantially compared with those of the same alloy produced by the conventional hot extrusion.
G. Hirt, A. Rassili, A. Bührig-Polaczek
J. Xu et al., "Microstructure and Mechanical Properties of Rheo-Extruded AZ31 Mg Alloy", Solid State Phenomena, Vols. 141-143, pp. 713-718, 2008