The aim of this research work was to investigate the impact that the traverse speed of a tool has on the microstructural changes, mechanical characteristics and fracture morphology of a pure copper butt weld joint that was welded by using the Friction Stir Welding (FSW) technique. The fixed FSW process parameters included a constant tool rotational speed of 1200 rpm, axial force of 5 kN, tool tilt angle of 0°, plunge depth of 0.3 mm, and dwell time of 5 s, which were maintained throughout the joining process. For the purpose of fabricating the weld joints between the copper plates a cylindrical tool equipped with a non-threaded tapered pin profiled FSW tool was utilized. Three tool traverse speeds 30 mm/min, 40 mm/min, and 50 mm/min—were employed, producing defect-free weld joints. Due to the sufficient amount of heat generation and thorough material mixing in the stir zone, the grains obtained at 30 mm/min were very fine, uniform, and evenly distributed. Quantitative analysis revealed that the minimum average grain size of 4.196 μm and maximum microhardness of 84 HV were achieved at 30 mm/min, with elongation of 10.66%, compared to 4.706 μm grain size, 70 HV hardness, and 8.15% elongation at 50 mm/min. The experimental results showed that the welded joint fabricated at 30 mm/min achieved the highest tensile strength of 215 MPa, which is approximately 85% of the base material strength. At a welding speed of 30 mm/min, a densely populated dimple structure was observed, which improved the joint's ductility. Due to the increasing number of applications for copper alloys there is a growing demand for welding in various industries due to the increasing use of copper in various applications such as switchgear, containers, heat exchangers, radiators, solar heaters, condenser tubes, propellers and water-cooled crucibles, there is a growing demand for effective welding techniques for joining these alloys. This current work revealed that the welding speed had a considerable impact on the copper CDA 101 friction stir welded joints.
Giridharan et al. (Wed,) studied this question.