Influence of pin profiles on temperature distribution, microstructure evolution and mechanical properties of friction stir welded AA6061

Abstract

The friction stir welded (FSWed) butt-joints of 6061 aluminium alloy were fabricated by various pin geometries including cylindrical thread, tapered thread, triflate tapered thread and cylindrical non-thread. The attention was put on the role of the pin geometries in temperature distribution, microstructure evolution and mechanical properties of the joints. The history of changing welding temperature is validated through both experimental work and numerical simulation. The results showed that the highest welding temperature was obtained about 480 °C at triflate tapered thread pin in both experiment and numerical simulation. In all cases, the tensile strength was reached approximately 200 MPa with the joint efficiency of 80% in comparison with base metal. The fracture location of the joints was found in the heat affected zone, where the lowest value of hardness was obtained. The stress of root bend was lower than that of face bend. Crack-free on the welding surface of face bend indicated that the joints are ductile. However, the specific influence of pin geometries on the microstructure evolution and mechanical properties of the joints is insignificant in this work.

Keywords:

• Friction stir welding
• pin profile
• aluminium alloys
• tensile strength
• coupled Eulerian Lagrangian

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was funded by the Vietnam National University Ho Chi Minh City (VNU-HCM) under Grant number C2022-20-09.