Solid-state bonding process induced highly synergistic mechanical properties of 6061 Al alloy joint by shear deformation

Obtaining a highly synergistic mechanical property between joint and base metal (BM) in aluminum (Al) alloy is a chronic problem. In this work, shear bonding technology is applied to a commercial 6061 Al alloy. The results show that a flat and uniform joint interface is obtained. The joint presents a highly synergistic mechanical property compared with BM, whether after shear bonding or heat treatment. The joint coefficient reaches 95.6% after shear bonding and exceeds 100% after heat treatment, which is better than the traditional connection method of aluminum alloy. The high joint coefficient mainly originates from the well-linked joint and gradient grain structure. The gradient grain structure is beneficial to activate more slip systems to coordinate plastic deformation. Although the fine-grained structure is sacrificed after heat treatment, higher strength and joint coefficient are obtained due to the higher work hardening. This newly developed method has a large potential for application to the infinite rolling of Al alloy sheets and can also be used for Al alloy connection in automobile, aerospace, rail transportation, and other fields. The findings in this work can provide essential theoretical support and application reference for the shear connection of Al alloy. © 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.