Laser beam welded joints of dissimilar heat treatable aluminium alloys

Vickers micro-hardness measurements were performed to fully characterize the heterogeneity in mechanical properties across the different zones of the dissimilar welds. Strain data acquisition by Digital Image Correlation (DIC) allowed to assess the influence of local weld properties on joints strength in tensile loading. The important role of the temper conditions of the parent materials, resulting from the different joint pre and post-welding heat treatment options, on the tensile behaviour of the skin and, in this way, on the global strength of the connection was showed. The dramatic role played by the Heat Affected Zone and the influence of the distribution of the strengthening elements on examined joints mechanical properties has been put in evidence, according to mechanical test results.