College of Materials Science and Engineering;
Chongqing University;
Chongqing 400044;
China;
National Engineering Research Centre of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composite;
School of Materials Science and Engineering;
Shanghai Jiao Tong University;
Shanghai 200240;
China;
Mg alloy; Extrusion; Bimodal-grained structure; Precipitation; Electron back scattering diffraction;