Production of Mg-Al-Zn magnesium alloy sheets with
ultrafine-grain microstructure by accumulative roll-bonding
ultrafine-grain microstructure by accumulative roll-bonding
(1. School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China;
2. National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials,
South China University of Technology, Guangzhou 510640, China)
2. National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials,
South China University of Technology, Guangzhou 510640, China)
Abstract: Accumulative roll-bonding (ARB) was applied to Mg-Al-Zn magnesium alloy sheets to prepare ultrafine-grain microstructure. Significant grain refinement is achieved after three cycles of ARB with average grain size of about 1.3 μm. The microstructure is characterized by nearly uniform ultrafine equiaxed microstructure without twins. The evolution of the misorientation distribution during ARB was measured by EBSD. Grain refinement can be contributed to the grain subdivision induced by severe accumulated strain, the accumulated strain enhanced concurrent dynamic recovery and recrystallization as well as the complicated distribution of interface and shear strain during ARB.
Key words: Mg-Al-Zn magnesium alloys; microstructure; grain refinement; dynamic recrystallization; misorientation