Structure and Properties of Dissimilar Joint of Ti and Al Alloys Obtained by Friction Stir Welding.

The paper deals with friction stir welding of Grade 5 Ti alloy and AA2024 Al alloy sheets based on liquid cooling of welded joints. The metallographic analysis shows the mutual Al and Ti dissolution in the stir zone of the welded joint. The fractographic analysis of the surface shows a non-uniform fracture in the weld zone due to unwelded areas and a brittle fracture due to the presence of intermetallic components, which, in turn embrittle welded joints. By varying the parameters of friction stir welding, the adhesion between the materials is improved to obtain a joint with the highest possible strength. [ABSTRACT FROM AUTHOR]