Design of aluminium solid self-piercing rivets for joining aluminium sheets by material and geometric modification

Abstract

Because of their excellent lightweight properties, aluminium alloys are processed in industries across the mobility sector. A suitable and efficient process for joining structural components made of aluminium sheet metal is solid self-piercing riveting (SSPR). It eliminates the need for time-consuming preparatory work, such as the insertion of pilot holes, while making the joining process highly automatable.Due to the process technology, the rivet itself first acts as a punching tool and then as a fastener to transfer the load of the joint. This leads to high requirements for the rivet in terms of strength and ductility.In this paper, a new rivet design will be presented that focuses on adjusting the rivet geometry, as well as the material, to enable sufficient functionality in the installation and operational phase. Consequently, aluminium sheet metal can be joined in a wider range of applications using aluminium-based SSPR. With this newly developed aluminium rivet, it is possible to join the aluminium alloy EN AW-6111 PX, which is widely used in the automotive industry, up to a total sheet thickness of 3.1 mm for the first time. This development contributes to aluminium-based lightweight structures and ensures a good recyclability.

Keywords

• Joining by forming
• Solid self-piercing rivet
• AA 7068
• EN AW-6111
• Heat treatment
• Fatigue