Experimental studies of laser welding of aviation-­grade aluminum alloys were carried out. To improve the mechanical properties of the welds, an integrated approach was applied, including laser welding in the optimal mode and post processing (quenching, intermediate plastic deformation, artificial aging) of the welded joints. For the first time, a comprehensive comparative study of the effect of heat treatment of welds and main alloys of the A5M, AMg6, 1420, 1424 and 1441 and B‑1469 grades was carried out. For all stages of heat treatment, the effect of the chemical composition of the alloy on the strength and microstructure of the weld is determined. As a result of this work, a complex technology has been developed for creating weld joints of modern high-strength, thermally hardened aluminum alloys, which includes laser welding and subsequent special heat treatment of samples.
Optimal laser welding modes were found that ensure the production of welds without defects in the form of open porosity, undercuts, cracks in the weld and the heat-affected zone. The postprocessing of welded joints obtained under optimal laser welding conditions was carried out on the basis of heat treatment (quenching + artificial aging). It is shown that, by changing the heat treatment regimes, it is possible to control the mechanical parameters of welded joint: strength and plasticity of the samples.
For the first time for welded joints obtained by laser welding and optimal post-processing for aluminum-­lithium thermally processed alloys, mechanical characteristics were achieved comparable to the value for the alloy in delivery condition.

DOI: 10.22184/1993-7296.FRos.2019.13.4.356.366


Разработка: студия Green Art