Study On Effect Of Welding Materials And Procedures On Weldability Of Aluminum Alloys

Because of its characteristics of lightweight, high strength and rigidness ratios, etc., aluminum alloys are praised as the optimizing and prospective material in engineering, are now having rising application in vehicles, ship building, construction, bridge, chemical machinery and aerospace industries. However, also because of its special physical and chemical properties, aluminum alloys are usually regarded as having poor weldability in terms of meeting the necessity of structural design. Thus, solving the problem of poor weldability of aluminum alloys becomes an urgent task.In the paper, the weldability of 5083 aluminum alloys is studied by using manual TIG welding. Imported welding wire ER5183, base metal 5083 and self-made ER5183 welding rod are used as filling materials. It can be concluded through the experimental results that standard ER5183 wire can be ideally used for 5083 alloy's welding, and the mechanical property of the resulted welding joint can meet the ASW criterion. When using the self-made ER5183 welding rod as welding material, the resulted weld is found to have pores, inclusions and surface micro cracks. Further research shows when the weld metal is under tensile stress, these pores and inclusions happen to be the initiation sites for micro cracks. While for the welding joint resulted from using 5083 alloy as the filling material, there is a slight decrease in tensile strength and that is believed to be caused by macro and micro segregation of alloy elements and the burning away of Mg element.However, the porosity problem of aluminum alloys can be avoided by appropriate choosing of welding process parameter and protective atmosphere. This paper introduces an apt protective gas shield that can reduce the rate of porosity even when the surface cleaning for welding material is not sufficient.