The hot rolling deformation performance of as-cast AZ80 magnesium alloy after ultrasonic processing

Abstract

Aiming at the poor formability of Mg alloys, this work investigated the hot rolling deformation performance and behavior of as-cast AZ80 alloy with ultrasonic processing (UP) using both experiment and finite element method (FEM) simulation. The results reflect that UP refined grains from 876 μm to 215 μm and eliminated the dendrites. The as-rolled sheet without UP had many intersectant shear bands with the appearance of micro-cracks but less DRX than the sheet with UP. The as-rolled sheet with UP had weakened basal texture with the intensity decrease from 14.14 (sheet without UP) to 6.86, and less content of contraction twins and double twins. Many cracks appeared on the surface of the as-rolled sheet without UP at both rolling temperatures of 573 K and 673 K. By contrast, the sheet with UP had a few small edge-cracks at 573 K and no cracks at 673 K. The FEM simulation revealed that as-cast AZ80 with UP required less effective stress and had less damage value during the rolling process than the sheet with UP. The UP presents the ability to refine the as-cast grains and to improve the formability of AZ80 in the subsequent deformation process.

Keywords

• Magnesium alloy
• Hot rolling
• Formability improvement
• Ultrasonic processing