Influence of Quenching and Subsequent Artificial Aging on Tensile Strength of Laser-Welded Joints of Al–Cu–Li Alloy

The research aim was to optimize post-weld heat-treatment (PWHT) modes for a laser-welded joint of the Al–Cu–Li alloy and improve their respective strength properties. As result, ultimate tensile strength, yield point, elongation were enhanced up 95%, 94%, 38%, respectively, those inherent in base metal. Before after PWHT, both microstructures phase compositions have been examined by optical scanning electron microscopy, as well synchrotron X-ray diffractometry. In as-welded metal, α-Al T1(Al2CuLi) phases found, along with θ′(Al2Cu) S′(Al2CuMg) localized at grain boundaries, significantly reducing mechanical properties joint. Upon quenching, agglomerates dissolved solid solution homogenized, Guinier–Preston zones precipitates intermediate metastable θ″ formed. After subsequent optimal artificial aging, (predominant) hardening θ′ (partial) observed weld which contributed improvement