Unveiling the deformation mechanism of highly deformable magnesium alloy with heterogeneous grains. (December 2022)

• Record Type: Journal Article
• Authors: Zhang, Zhi; Zhang, Jinghuai; Wang, Wenke; Liu, Shujuan; Sun, Bin; Xie, Jinshu; xiao, Tingxu
• Is Part Of: Scripta materialia. Number 221(2022)
• Publication Date: 2022-12
• Subjects: Magnesium alloys -- Heterogeneous grains -- Deformation mechanism -- Work-hardening capacity; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2022.114963
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Poor formability at room temperature is a key problem that limits the application of Mg alloys. Formability is closely dependent on both large work-hardening capacity and high tensile elongation. Herein, we develop a Mg-3Al-1Zn-0.4Mn (wt%) alloy with heterogeneous grains, obtaining an exceptionally high difference between ultimate tensile strength (UTS) and yield strength (YS) (UTS−YS: 164 MPa) and a good tensile elongation (22%). The uneven deformation of large and small grains is mainly affected by the size difference between grains rather than texture. The high strain hardening is attributed to the pile-up of geometrically necessary dislocations at grain boundaries between large and small grains due to uneven microstrain. The fraction of non-basal dislocations increases greatly with the increase of tensile strain, contributing to the improved ductility. Thus, we put forward a new strategy for improving the formability potential of Mg alloys via introducing heterogeneous-grained structure. Graphical abstract: Image, graphical abstract