Friction element riveting: a novel aluminum to aluminum joining process

Abstract

Multimaterial joining has become necessary to continue to reduce vehicle mass in order to further improve fuel economy. Novel processes continue to be developed which are capable of joining various materials. Friction element welding (FEW) is one such process used to join aluminum and steel sheets. This process is well known for its rapid process times, typically less than two seconds, and its extraordinary robustness. FEW is also capable of joining aluminum sheets to the strongest steels used in automotive bodies.A derivative of the FEW process was explored, termed friction element riveting (FER). This process is used to perform aluminum to aluminum joining and shares many of the same benefits as FEW. For example, there remains no need for pre-hole drilling, a distinct advantage of the FEW process. Several strength metrics and the influence of process parameters are defined herein. It was determined that FER is a viable process for use in industrial applications. Through parameter optimization of the welding step, the joint resulted in a cross tension strength and transverse shear strength of 7.37±0.31 kN and 21.4±1.21 kN, respectively, which makes it a competitive technology for similar joining methods.