Influence of the silicon content on the mechanical properties of AA6xxx laser welds

The mechanical properties of Al-Mg-Si laser welds have been investigated as a function of the silicon content in the fusion zone which depends on the amount of the Al-12%Si filler wire used during welding. The results show that not only the tensile strength but also the fracture strain increase when the silicon content increases. This behaviour is explained by a better homogeneity of the local strains in the different zones of the welds when the silicon content increases. Finite element simulations taking into account the local mechanical properties of the various zones allow predicting the mechanical response of the macroscopic weld in tension.