Enhanced strength and ductility of rapid cooling friction stir welded ultralight Mg–14Li–1Al alloy joint

• DOI: 10.1016/j.jmrt.2023.02.083
• Publication Date: 2023-02-20T04:46:30Z
• Authors: Nan Xu; Zhong-hao Qiu; Zi-ke Ren; Jun Shen; Dan Wang; Qi-ning Song; Jian-hua Zhao; Yong-feng Jiang; Ye-feng Bao
• Keywords: Friction Stir Welding; Ductility (Earth science); Elongation

Ultralight Mg–14Li–1Al alloy sheets were subjected to conventional friction stir welding (FSW) and rapid cooling FSW (RCFSW) for comparative study. Compared with decreasing the rotation rate, use of coolant significantly improved thermal cycle inhibited grain coarsening. The RCFSW600 joint had an ultrafine structure its average size 2.1 μm. yield strength was mainly determined by synergic influences boundaries, dislocations, nanoscale MgLiAl2 precipitations. ultimate tensile 181 MPa efficiency reached 94.3%. A relatively good fracture elongation 9.6% also obtained. Finally, strength-ductility synergy regarded as interaction among deformation twins, stacking faults.