Improved microstructure and mechanical properties of friction stir-welded AZ61 Mg alloy joint

• DOI: 10.1016/j.jmrt.2022.03.160
• Publication Date: 2022-03-31T16:20:11Z
• Authors: Nan Xu; Zike Ren; Zhengda Lu; Jun Shen; Qining Song; Jianhua Zhao; Yefeng Bao
• Keywords: Friction Stir Welding; Dynamic Recrystallization; Ductility (Earth science); Recrystallization (geology)

Friction stir welding (FSW) is a common and effective technology used to join metals or alloys of low melting point. However, the FSW Mg alloy joint usually exhibits an unsatisfactory combination strength ductility due intense basal texture formed in welded joint. In this study, large-load low-speed was conducted on AZ61 improve thermal cycling during process. The exhibited ultrafine grain structure with high dislocation density large {10-12} twins. This refinement attributed continuous dynamic recrystallization twinning-induced geometric recrystallization. appearance twins played critical role randomization During transverse tensile testing, fractured at base metal, indicating that efficiency 100% successfully achieved. Compared conventional FSW, enhanced zone boundary strengthening, precipitation strengthening. elongation increased Schmid factor interaction between dislocations study provides facile strategy for enhance gives new insights improved strength-ductility synergy alloy.