DefinePK

Abstract

The fracture toughness of dissimilar aluminum alloys butt-joined by Friction Stir Welding (FSW) is studied. The aluminum grades used in this project were 5083 and 6061. The feasibility of using conventional belt-driven milling machine to perform FSW was also investigated by adding a custom-made compact clamping jig and FSW tool bit to the machine set up, and by varying machine parameters such as tool rotational speed (?, rpm), tool traverse speed (v, mm/min), plunge depth (mm) and tool tilt angle. Premilinary FSW runs were done with the milling machine to modify it for the purpose of FSW. Two types of test were carried out which were tensile test and single edge notch tension (SENT) test. Both tests were performed on a Universal Testing Machine (UTM). By visual inspection, tunnel defect was seen in SENT specimens and in the dissimilar grade FSW joint for tensile testing specimen. The similar grade FSW joints performed less than their base material in terms of tensile strength. The critical stress intensity factor (SIF) for the welded specimens were found to be lower than critical SIF values known from literature for their respective materials.