Strengthening the HAZ of an MIG welded joint of 6082-T6 aluminum alloy via mechanical-thermal hybrid aging treatment

Abstract

In this work, mechanical vibration was applied to the weldment during welding. This technique is called simultaneous mechanical aging and combined with post-weld thermal aging to form a mechanical-thermal hybrid aging process that was used to strengthen the HAZ of the MIG welded joint of 6082-T6 aluminum alloy. The HAZ softening was significantly reduced through the mechanical-thermal hybrid aging treatment, thereby substantially enhancing the joint strength. The β″ precipitated by post-weld thermal aging and the α precipitated by simultaneous mechanical aging give rise to precipitation hardening in the HAZ and therefore strengthen the HAZ. Degassing of the weld pool and grain refinement in the weld can be achieved by means of mechanical vibration to stir the weld pool. The fracture of welded joints is ductile fracture.

Keywords:

• Aluminum alloy
• MIG welding
• HAZ softening
• mechanical-thermal hybrid aging

Acknowledgments

The authors would like to thank the Natural Science Foundation of the Jiangsu Higher Education Institutions of China.

Disclosure statement

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

Additional information

Funding

This work was supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (No. 22KJA460011).