Friction Stir Welding of Lap Joints Using New Al–Li Alloys for Stringer-Skin Joints

Abstract

The aeronautic industry is continuously looking for new structural concepts with the aim of reducing dangerous gas emissions as well as reducing manufacturing costs and times. The development of advanced lightweight structures is an effective alternative to achieve the mentioned goals. Reinforced panels produced by the third generation aluminum–lithium alloys and Friction Stir Welding (FSW) can bring new solutions for more efficient aircrafts. This work presents the results obtained in the development and characterization of FSW joints directed to reinforced panel manufacturing. FSW lap joints were produced using aluminum–lithium alloys AA2099-T83 extrusions and AA2060-T8E30 sheets. Several welding parameter combinations and FSW tool designs were used to produce the joints. Joint properties were investigated by metallographic examination, microhardness tests as well as mechanical strength testing. The appropriate FSW conditions to optimize joint properties were established.