A Novel Method to Achieve Synchronized Enhancement of Strength and Ductility and In-Plane Mechanical Isotropy of Rolled Mg Sheets

A novel method referred as electric-associated corrugated wide limit alignment (E-CWLA) was proposed to address the contradiction between strength and plasticity of Mg sheets. The control group without electricity is referred to CWLA. Lots of tensile twins (TTs) was induced in CWLAed sample R300, and dynamic recrystallization (DRX) occurs. Strong transverse direction (TD)-titled texture accounts for the huge difference in yielding strength between different loading directions. Compared with parallel and thick TT lamellae, crossed and thin lamellae is beneficial to DRX and basal slip. Loading direction significantly influences the Schmid factors of prismatic and pyramidal slips of R300, which is the main reason for different ultimate tensile strength (UTS) and ductility of R300 along different directions. E-CWLAed sample E300 presents good in-plane mechanical isotropy with the maximum UTS of 272.1 MPa, yielding strength of 213.6 MPa and elongation of 22.7%, increasing by 32%, 53% and 83%, respectively. Regardless loading direction, similar Schmid factors of basal and non-basal slips greatly facilitates uniform plastic deformation and mechanical isotropy of E300. The special microstructure including lots of fine grains, some large grains and TTs results in a bimodal basal texture with very weak TD-titled component promotes its good deformation compatibility.