Comparison and Analysis of the Effect of Tools with Pins of Different Cross-Sections in the Friction-Stir Welding Method
Subject Areas :
Aala Hadi Bejai Almayali
1
,
Ahmad Afsari
2
*
,
Seyed Mohammad Reza Nazemosadat
3
,
Mohammad Marzban
4
1 - Department of Mechanical Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran
2 - Department of Mechanical Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran
3 - Department of Mechanical Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran
4 - Department of Mechanical Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran
Keywords: Friction Stir Welding, Aluminum Alloy, Tool Geometry, Microstructure, Mechanical Properties,
Abstract :
Friction Stir Welding (FSW) is a solid-state welding method that serves as a suitable alternative to fusion welding for materials such as aluminum, copper, magnesium, and even steel alloys. In this research, samples of Al 5754 H22 and Al 6063 T4 were welded using FSW. The tools employed in this study featured cylindrical and conical pins, both with and without threads. The tool material was H13 hot-worked steel, hardened to 52 ± 2 Rockwell C. The FSW process was performed using a vertical milling machine. The results indicate that the shape of the pin significantly affects the weld structure and its mechanical properties. The pin's geometry greatly influences the flow of plastic materials, as different pin designs employ various material transfer techniques. Consequently, modifying the geometry of the tool pin can enhance the process for joining dissimilar materials. The highest welding quality was achieved with the tool featuring a threaded conical pin, which resulted in a visually appealing weld with no obvious defects. The microstructure of the weld was fine, and the distribution of sediment was uniform with small sizes. The hardness tests revealed that changes in tool geometry did not significantly affect the hardness levels. However, the threaded conical tool provided the highest tensile strength for the weld, with the tensile strength of the weld joint reaching up to 75% of that of the base metal.