Study on friction stir welding of 2A97 Al-Li alloy

The weldability of 2A97 Al-Li alloy was studied using different friction stir welding variables in this paper. The results showed that the tensile strength and the elongation rate decreased with the increasing of the rotation speed. With the increasing of the welding speed, the tensile strength firstly increased to a maximum value then decreased. The maximum tensile strength was 373 MPa, which reached to 69% of that of the base metal, when the rotation speed was 600 r/min and the welding speed was 200 mm/min. The joints were mostly fractured at the weld nugget. Most of the precipitated phases in the weld nugget and the heat affected zone were decomposed. The precipitate density in the heat affected zone was higher than that in the weld nugget.