MICROSTRUCTURE AND TENSILE STRENGTH OF FRICTION STIR WELDING OF AL-CU

Friction Stir Welding (FSW) is a relatively new solid state joining technique which is used not only for joining the aluminium and its alloys but also has potential for joining dissimilar materials with very different physical and mechanical properties that are hard to weld using conventional fusion welding processes. FSW of aluminium and its alloys, and other similar material joining have now been commercialised in the automotive, aerospace, and marine industries; and recent interest is focused on joining dissimilar materials in developing effective manufacturing processes based on friction stir welding for electrical connecting and terminal products. There have been a reasonable number of studies in the literature on microstructure and fracture behaviour under static loading and very few studies on cyclic loading of FSW of dissimilar materials. However, a better scientific understanding in a number of aspects is required. This include interface phenomena during FSW of dissimilar materials with large differences in melting temperatures, how exactly the microstructure in the interfacial region is related to fracture behaviour when subjected to static is far from being fully understood. Thus, this study aims to understand the joint formation and the effect of interface microstructure on fracture behaviour under static and cyclic loading and how the FSW parameters affect the interface microstructure and fracture behaviour during FSW of dissimilar materials