Enhancing the Mechanical Properties of AZ80 Alloy by Combining Extrusion and Three Pass Calibre Rolling

Abstract

An AZ80 alloy with ultra-high strength and good ductility has been successfully prepared by a novel processing route of combining extrusion and caliber rolling. The caliber rolled (CRed) AZ80 alloy has a necklace grain structure with ultrafine dynamic recrystallized (DRXed) grains formed around the micro-scale deformed grains, which is remarkably different from the uniform microstructure of as-extruded sample free from caliber rolling. In addition, both the deformed region and the DRXed part in CRed AZ80 alloy exhibit more random basal texture than that of the as-extruded sample. Furthermore, the CRed AZ80 alloy demonstrates an excellent comprehensive mechanical property with the ultimate tensile strength of 446MPa and elongation of 13%, respectively. These good mechanical properties of CRed AZ80 alloy can be attributed to the synthetic effects of necklace bimodal microstructure containing ultra-fine grains, profuse Mg17Al12 precipitates, and the modified texture.