Microstructure and Eddy-Current Analysis of Aluminum 01570 Welded Joints Obtained by Friction Stir Welding

The article presents the results of studies of aluminum alloys connected by a welded joint obtained by friction stir welding. During this kind of welding a recrystallized fine-grained microstructure is formed in the joint. The pictures of the weld area microstructure are presented, and the eddy current probe signal variations when scanning the joint are shown. The resulting parameter of the eddy current probe was the local electrical conductivity of the weld area. It is demonstrated that the average grain size of the welded joint microstructure varies in the area of weld defects, which was determined by the signal variation of the eddy current probe. The microstructure peculiarities formed in the weld area where the defects are located, and their influence on the mechanical properties of welded joints are discussed. The results of a series of experiments allow concluding about the qualitative characteristics of the obtained welded joints.