Abstract
This paper deals with an experimental investigation on the friction stir welding of pure copper. 4 mm thick copper plates have been welded in the butt joint configuration using a conical unthreaded tool, with and without preheating. An electrically heated backing plate has been employed to increase the initial temperature of the plates and to investigate the influence of pre-heating on the weld ability of the considered material. The welded joints have been analyzed by means of macroscopic and microscopic observations, microhardness measurements and tensile tests. Obtained outcomes suggest that more complex pin shape is needed to promote an adequate material flow without preheating.
Highlights
Friction stir welding (FSW) is a solid-state welding process, developed and patented by The Welding Institute (TWI) of Cambridge in 1991
Most of researchers support the similarity of the FSW with the extrusion process in proximity of the pin, assisted by forging action played by the shoulder
Despite the intriguing advantages provided by the FSW process, in the case of copper welding one of the main drawbacks is related to some conditions to be satisfied to induce an opportune material flow
Summary
The softened material is forced to flow around the pin, from the front (leading edge) to the rear (trailing edge) according to complex patterns, resulting in a solid state weld [1, 2]. Most of researchers support the similarity of the FSW with the extrusion process in proximity of the pin, assisted by forging action played by the shoulder. This hypothesis is supported by the formation of periodic band structure, namely onion rings, observed in some materials and whose spacing is strictly related to process parameters [2,3,4]. What is more, published results are often contrasting and a convergence of the scientific community on some issues, such as the characteristics of the different welding
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
