PNNL

Abstract

In this study, we report the first experimental evidence of successful dissimilar metal joining of 6061-T6 aluminum alloy and DP590 steel via friction riveting. The surface morphology and microstructure reveal the formation of mechanical interlocking and metallurgical bonds at the joint interfaces, resulting in a load carrying capacity of 5.7 kN during lap shear tensile testing at room temperature. We conducted microstructural analyses of the joint cross sections and post-lap-shear fractography to study the fracture mechanism of these joints. A finite element analysis model accompanied the tests to help interpret the role of mechanical interlocking and metallurgical bonding in the failure during lap shear tests. Experimental results are in good agreement with finite element–based modeling efforts. This study indicates that friction riveting is an excellent candidate for aluminum-to-steel dissimilar joining, such as in automotive applications.