Effect of Mg and Cu on mechanical properties of high-strength welded joints of aluminum alloys obtained by laser welding

Results of experimental investigations of welded joints of high-strength aluminum-lithium alloys of the Al–Cu–Li and Al–Mg–Li systems are reported. The welded joints are obtained by means of laser welding and are subjected to various types of processing for obtaining high-strength welded joints. A microstructural analysis is performed. The phase composition and mechanical properties of the welded joints before and after thermal treatment are studied. It is found that combined thermal treatment of the welded joint (annealing, quenching, and artificial aging) increases the joint strength, but appreciably decreases the alloy strength outside the region thermally affected by the welding process.