High Strain-Rate Compressive Characteristics of Friction Stir Welded AA2024-T3 Joints in Through-Thickness Direction

Abstract

High strain-rate compressive stress-strain characteristics of AA2024-T3 and its welds as produced by the friction stir welding (FSW) process are investigated using the conventional split Hopkinson pressure bar. Friction stir welded AA2024-T3 joints are made under a fixed set of appropriate welding conditions. Cylindrical specimens machined along the thickness direction of both the base material and the friction stir weld nugget region are used in the static and impact compression tests. It is shown that the compressive flow stress of the weld nugget is reduced by 7 to 11 % compared with that of the base material, and that both the base material and the weld nugget exhibit almost no strain rate effect up to nearly =103/s. The Ramberg-Osgood equation can be used to describe the compressive stress-strain behavior at low and high rates of strain.