Comparative study of the high-temperature behaviour of Mg–Al and Mg–Zn wrought alloys

The high-temperature workability of AZ31 has been extensively investigated in recent years, since this alloy is considered the best candidate for production of wrought components in Mg. While peak flow stresses, and thus working loads during rolling, extrusion or forging, seem to weakly depend on the initial microstructure, the same conclusion does not hold for the ductility of the alloy. Fewer Studies have considered the high temperature workability of Mg-Zn alloys. This study aims at relating the mechanical response of the materials, in term of flow stresses and strain to fracture, with the chemical composition and the prior microstructure. The results of mechanical testing in torsion, carried Out in the same regime of temperature and strain rates were then analysed and discussed. Constitutive equations relating flow stresses to straining conditions were obtained for each tested alloy, and the differences in strain-to-fracture were closely analysed.