Study of friction stir welding of 01420 aluminum–lithium alloy

The 01420 Al–Li alloy plates were friction stir welded at different welding parameters. The effect of welding parameters on the quality of the 01420 Al–Li friction stir welded joints was investigated. As a result, the optimized combinations of various welding parameters (pin rotation speed, welding speed and welding pressure) were identified. By comparison of the heat inputs during welding process at different parameter combinations, the relationship between the grain size in the stirred zone (SZ) and the welding parameters was established. Furthermore, the mechanical properties of the defect-free joints under different heat inputs were investigated. The experimental results showed that the maximum ultimate strength of the joints is equivalent to 86% that of the base material and the maximum bending angle of the joints can reach 180°.