Electrical conductivity as an indicator of friction stir welded aluminium lap joint quality

Friction stir welding has proven to be a good process for joining materials because the welded joint has good mechanical properties. The aim of the study is to examine the electrical conductivity of the welded joint, because of its effects on quality of a welded joint, i.e., on the homogeneity of the structure. By experimentally welding two aluminium plates of thickness 3 mm, AA5754-H111, a lap joint is obtained. The paper provides a description of technological parameters for experimental welding, the macrostructural images of the joint and electrical conductivity of the joint. The joint is successfully welded with the selected technological parameters. The macrostructural images clearly show the nugget zone as well as the joint without defect type bonding line (kissing bond). Measurements that are made show that electrical conductivity is almost constant over the entire section of the joint, from the base metal zone to the weld zone which indicates that the mixing in that part is excellent and that a homogeneous material is obtained in the weld zone.