| 2026 №04 (03) | 2026 №04 (05) |
"Avtomatychne Zvaryuvannya" (Automatic Welding), #4, 2026, pp. 38-44
Structure and microhardness of copper alloy butt welded joints produced by friction stir welding
A.Yu. Tunik
, L.I. Adeeva, M.A. Polieshchuk, S.G. Hryhorenko
E.O. Paton Electric Welding Institute of the NAS of Ukraine
11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine.
Е-mail: allatunik@gmail.com
The paper presents the results of investigation of the influence of the technological parameters of friction stir welding (FSW) process on the structure and microhardness of butt welded joints of grade M1 technical copper. The FSW process takes place through plastic deformation of the metal heated up to the recrystallization temperature without melting. It was found that the process temperature is determined by the area of interaction of the FSW tool with the metal of the plates being joined. The work is a study of the influence of axial loading (shoulder penetration depth) and welding speed on the structure and microhardness of copper welded joints. Increase in shoulder depth from 0.2 to 0.6 mm with other FSW parameters being constant leads to lowering of microhardness of all the other joint zones maximum by 15 % due to higher heat input. Weld height decreases by 7 %, and the main weld metal structure becomes more homogeneous. Welding speed increase from 25 to 100 mm/min with other FSW parameters being constant has no significant influence on weld dimensions. At welding speed of 40 mm/min., which ensures optimal heat input, no defects were found in the welded joint. A dense defectfree structure with fine grains and microhardness close to that of the base metal forms in the joint zone. 12 Ref., 2 Tabl., 6 Fig.
Keywords: friction stir welding, FSW tool, technological parameters, copper joints, structure, properties
Received: 08.10.2025
Received in revised form: 21.12.2025
Accepted: 20.07.2026
Posted online: 24.07.2026
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