Mechanical Property of Friction Stir Welded Butt Joint in 2 mm Thick Aluminum Alloy

摘要

Two sizes of welding tool are used to prepare friction stir welded butt joint of 2024-T3 Aluminum alloy of 2mm thickness and their mechanical properties are evaluated. Indentation hardness tests revealed that typical hardness reduction is not necessarily observed on the section of the welding line. This result is different from that for thicker FSW plate. Static tests result indicates the yield stress for FSW joint is equal or a little higher than that for base material, while its ultimate strength is a little lower than that for base material. Fatigue test result indicates the several types of fatigue fracture origin such as LOP, burr, tool mark and etc are observed. Because the LOP, the tool mark and the burr exists along the welding line, these might cause multiple fracture origin and it might decrease the fatigue life significantly. Although the size of weld tool affected the size of the tool mark and the burr of the FSW, even smaller burr could be the fracture origin and affected the fatigue life.