Evaluation of the strain behaviour of butt joints on AZ31 magnesium alloy thin sheets welded by Nd:YAG laser

In this work, the mechanical and technological behaviour of AZ31 magnesium alloy laser welded joints is investigated. The forming behaviour of the joints is analysed by both tensile and biaxial stretch tests. Each test is monitored using a digital image correlation system in order to acquire the complete strain field during the whole test. Both in tensile and biaxial stretching tests, the strain maps reveal that the weld bead makes the strain path experienced by the welded specimen more critical than the one experienced by the base material, and this can be related to morphological defects of the weld bead.