Temperature-Dependent Fracture Loci of AZ31 Magnesium Alloy Sheets

Magnesium alloys have been used in the automotive and aerospace industry for several years, thanks to their high strength-to-density ratio. Their mechanical characteristics at room and even at elevated temperature have been well studied, whereas, when it comes to temperatures lower than room one, only a few studies are available in the literature. To this aim, the present paper investigates the mechanical behavior of AZ31 magnesium alloy sheets deformed at different temperature regimes. Tensile tests till fracture were carried out at room temperature, −100, −50, 100, and 300 °C using different specimen geometries in order to vary the stress triaxiality. The fracture strain values were identified making use of a combined numerical–experimental approach, whereas the fracture surfaces were qualitatively characterized by means of stereoscopy and scanning electron microscopy. Finally, the AZ31 fracture locus as a function of the stress state and temperature was constructed.