STUDY OF MICROSTRUCTURE AND MECHANICAL PROPERTIES OF FILLET T-JOINT ALUMINIUM ALLOY 5052-H34 WELDED THROUGH FRICTION STIR WELDING (FSW) METHOD

• Main Author: Ardi Anto, Bayu
• Format: Final Project
• Language: Indonesia
• Subjects: Metalurgi
• Online Access: https://digilib.itb.ac.id/gdl/view/51350
• Institution: Institut Teknologi Bandung

Aluminium is a lightweight metal that the need is increasing. One of the most widely used aluminium alloys is 5052 series. Aluminium alloy 5052 has excellent corrosion resistance in the seawater environment, so it is widely used in the construction in the nearshore and marine. Friction Stir Welding (FSW) in recent years has been quite successful in the welding process of aluminium alloys. FSW is a solid-state welding method that has advantages that cannot be obtained by other conventional welding methods. However, because the FSW process does not require filler material (autogenous welding), in principle the fillet joint welds type cannot be done with the FSW method. Development has been carried out on the FSW process so that the fillet T-joint can be produced with this method. In this research, microstructure and mechanical properties were studied in fillet T-joint aluminium alloy 5052-H34. The experiment was started by cutting the fillet T-joint aluminium alloy 5052-H34 specimen according to the specified size. Specimens for observation of microstructure were prepared by sanding and polishing. The specimens were carried out electro etching in 2.5% HBF4 solution, before the specimens were observed using an Optical Microscope (OM). Scanning Electron Microscope (SEM) was also used. Hardness testing was carried out on the same specimen in microstructure observation. The fillet T-joint specimen was prepared so that it could be installed in a tensile testing machine, and then tensile strength testing was carried out. There are four microstructure zones that appear on the fillet T-joint aluminium alloy 5052-H34 welded through the FSW method. The microstructure zones are the nugget zone, thermomechanically affected zone (TMAZ), heat affected zone (HAZ), and base metal zone. The hardness of the weld area depends on the microstructure. The zone that has the highest hardness is the nugget zone, with an average hardness value (HV) 73.67. While the zone with the lowest hardness is HAZ, with an average hardness value 65. The base metal zone has an average hardness value 69.4. Hardness value on TMAZ is difficult to know because of the narrow zone area. The tensile strength value of fillet T-joint aluminum alloy 5052-H34 welded through FSW is 132 MPa. This value is lower than the tensile strength value of the base metal. This is because of the kissing bond defects in the weld area.