Hot tensile deformation behavior and microstructure evolution of Mg–Mn–Ce alloy

Abstract

Magnesium-manganese series alloys, as materials with very low-density value, have excellent mechanical properties and corrosion resistance, and have broad prospects in automotive, aerospace, biomedical and other fields. In this work, the thermal deformation behavior and microstructural evolution of Mg–Mn–Ce alloys were investigated through uniaxial hot stretching experiments on Mg–Mn–Ce alloy plates under different deformation conditions, with the main focus on the plastic deformation mechanism of Mg–Mn–Ce alloys under different forming conditions. The unified viscoplastic constitutive equation for coupled damage is developed and compared with different types of constitutive equation models. Remarkably, the decrease in peak stress with increasing temperature or decreasing strain rate in Mg–Mn–Ce alloys is due to the fact that the internal slip system of the material is more easily activated with increasing temperature. As the temperature increases, the dislocations within the material decrease, which is due to the fact that the temperature increase makes the DRX action progressively stronger than the dislocation action, and the DRX leads to a significant coarsening of the grains at 573 K. In addition, the fracture behavior of the alloy under different deformation conditions has also been investigated, and the fracture pattern of Mg–Mn–Ce alloys transitions from pronounced cleavage fracture to the appearance of dimples and finally to ductile fracture with a large number of dimples as the temperature increases.

Keywords

• Magnesium–manganese–cerium alloy
• Hot tensile deformation
• Microstructure evolution
• Constitutive equation
• Fracture morphology
• Thermal deformation parameter