Self-riveting friction stir lap welding of aluminum alloy to steel

• A novel self-riveting friction stir lap welding technique is developed.
• A self-riveting structure forms with plasticized aluminum and imposed pressure.
• The self-riveting structure can bear load even tearing of interfacial bonding.
• The self-riveting structure is beneficial to prevent total failure of joint.
• Enlarged elongation enables joint to function under fluctuating load.

A novel self-riveting friction stir lap welding technique was developed by the prefabricated holes to realize sound and effective joining of 6082-T6aluminum alloy to QSTE340TM steel. Partial dynamic recrystallized aluminum flows downwards and fills the prefabricated holes forming self-riveting structure. Metallurgical bonding as diffusion layers formed at the interface of Al/Steel. The joint fracture process contains separation of self-riveting structure and unilateral hole wall, tearing of metallurgical bonding and final failure of self-riveting structure. An average fracture load of 3.21 kN is obtained, which is stronger with high average elongation than that without prefabricated holes. The self-riveting structure is beneficial to prevent total failure of different materials joints with applicative perspectives.

Figure optionsDownload as PowerPoint slide