Friction stir weld of 2060 Al-Cu-Li alloy: Microstructure and mechanical properties

This paper investigated the microstructural and mechanical properties of 2060 Al-Cu-Li alloy and its sound friction stir joints. The base materials present large pan-cake grains whereas the nugget zone of friction stir weld exhibits fine grain structure. Dispersions are aligned along rolling direction in the base material. They were re-distributed and uniformly decorated within the weld nugget. The base material is mainly strengthened by T1 precipitate with small amounts of θ′ and S′. The various strengthening precipitates were dissolved in the nugget zone where dense dislocations and nano-sized co-clusters were found. Additionally, the hardness, tensile strength and fatigue life limit of the joint are measured.