Investigation of welding quality and internal elongation problem in aluminum extrusion

Abstract

AA6082 aluminum alloys are particularly useful in heavy industry and machinery manufacturing given their mechanical properties, but when extruding complex profiles used in these sectors, one of the main problems is the welding problem. In order to prevent the welding defects by suitable die design, two different porthole extrusion die set were designed and manufactured using different design techniques in this study. Extrusion trials were conducted for each die. The analysis examined how die design affects profile exit temperature, stress and strain distribution, and billet interface. It also aimed to characterize the effect of die design on welding quality through tensile tests, hardness tests, and microstructural observations. The results show that tapering the mandrel and die plate parts at an angle causes compression of the material flow and reduces the volume of the weld chamber and helps to direct material to the critical regions. This design approach offers a solution for the welding problem of complicated profiles.