Dissimilar friction stir lap welding of AA2198 and AA7075 sheets: forces, microstructure and mechanical properties

Abstract This paper investigates the dissimilar friction stir lap welding of AA2198 and AA7075 sheets. The influence processing parameters, namely speed tool rotational on joint features, microstructure, mechanical properties were studied by implementing a full factorial design experiments. Axial transversal forces continuously measured during process using sensed fixture aiming at correlation forces, quality achieved joints. Obtained outcomes showed hook formation for all combination parameters existence very narrow window in which it is possible to avoid internal defects, such as grooves tunnels. weld bead morphology shear strength was elucidated proving that ruled morphology. microstructure joints discussed considering also microhardness distribution. Graphical abstract