Mechanical behavior and microstructure evolution of AZ31 magnesium alloy sheet in an ultrasonic vibration-assisted hot tensile test

Ultrasonic vibration-assisted tensile tests of AZ31 magnesium (Mg) alloy sheets are carried out at different temperatures (150 degrees C, 200 degrees C) and amplitudes (0-11.2 mu m). The influences of the ultrasonic vibration on the stress-strain responses, microstructural evolution, fracture morphology, dynamic recrystallization (DRX), and dislocation structure of the material during hot deformation are discussed. The results show that both flow stress and elongation of the material are significantly influenced by the temperature and amplitude. The application of ultrasonic vibration delays the occurrence of DRX. However, it accelerates the continuous dynamic recrystallization process, thereby increasing the percentage of the DRX. Furthermore, an evolution of the dislocation structure occurs under the impact of ultrasonic vibration, offering valuable insights into the plasticity improvement of the material. The underlying mechanisms of ultrasonic vibration-assisted hot deformation of AZ31 Mg alloys can be described as below. Ultrasonic vibration affects the motion and distribution of dislocations, which have an effect on the dynamic recrystallization behavior, ultimately leading to changes in mechanical behavior of the material. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study conducted ultrasonic vibration-assisted hot deformation experiments on AZ31 magnesium alloy sheets, revealing significant effects on mechanical properties and microstructural evolution, such as delayed occurrence of dynamic recrystallization and accelerated continuous dynamic recrystallization leading to improved material ductility.