A comparative study of microstructure and mechanical properties of conventional and synergistic double-sided FSW joints of 6061 zxaluminium alloy

Abstract

In this study, synergistic double-sided friction stir welding (DS-FSW) is proposed to solve the problems of large deformation and the time-consuming of traditional DS-FSW. The microstructure, mechanical properties, and fracture paths of novel and conventional joints are studied under different welding parameters. Results show that defects in novel joints have been improved. However, the grain size in the stir zone of novel joints is larger than that of conventional joints. The microhardness map of the novel joint shows a more uniform distribution compared to that of the conventional joint. At a rotational speed of 1800 rpm and transverse speed of 1000 mm min⁻¹, the distortion of the novel joint and conventional joint is 0.1 and 1 mm, respectively. The tensile force of novel joints is higher than that of conventional joints for the same welding parameters. The maximum tensile force of novel and conventional joints is 36.8 and 34.9 kN, respectively.

KEYWORDS:

• Friction stir welding
• conventional double-sided FSW
• synergistic double-sided FSW
• 6061 aluminium alloy
• microstructure
• mechanical properties
• distortion

Disclosure statement

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

Data availability

The processed data required to reproduce these findings cannot be shared at this time as these data form part of an ongoing study.

Additional information

Funding

The authors gratefully acknowledge the financial support of the National Natural Science Foundation of China (52174374 and 51975479), the State Key Laboratory of Solidification Processing (NPU, China) (2021-TZ-01), and the Research Fund of the State Key Laboratory of Solidification Processing (NPU, China) (2022-BJ-02).