Tensile fracture prediction of AZ31 cast-rolled sheet based on hot working map

Abstract

Uniaxial thermal tensile testing at a wide temperature range (473–723 K) and strain rate (0.01-1s−1). The isothermal hot tensile deformation and fracture behavior of AZ31 magnesium alloy in cast-rolled state was investigated using the Gleeble-3800 thermomechanical simulator. Based on the real stress-strain data, the thermal processing diagrams of the isothermal hot tensile tests were established. The effects of deformation parameters on strain hardening rate, microstructure evolution and fracture form in hot tensile tests were investigated. The results showed that the rheological stress increases with increasing strain rate and decreases with increasing deformation temperature. The optimum process parameters for the cast-rolled state of AZ31 Mg alloy were determined from the thermal processing diagram. With increasing temperature and decreasing strain rate, the transformation of deformation mechanism and fracture type in magnesium alloy is closely related to the deformation of twinned and recrystallized structure.

Keywords

• AZ31 Mg alloy
• Hot-deformation behavior
• Microstructure
• Cracking