Electrically-assisted mechanical clinching of AA6061-T6 aluminum to galvanized DP590 steel: effect of geometrical features on material flow and mechanical strength

Abstract

The mechanical clinching as an alternative joining process for fabricating lightweight aluminum to steel assemblies may face the challenges when joining low-ductility aluminum alloy to high-strength steel. Several researches have been focused on applying the electrically-assisted processes in various fields due to energy efficiency as well as practical simplicity, in order to improve the formability. This paper concentrates on the electrically-assisted mechanical clinching (EAMC) of AA6061-T6 aluminum to galvanized DP590 steel. To this end, a combination of experimental and numerical clinching tests was performed using extensible die at different penetration depths, in which controlling the material flow was obtained by applying newly defined chamfer ratio RC in order to guarantee the strong mechanical interlock. The joint section parameters, failure loads, and failure modes were measured. The effects of the geometrical features on material flow and mechanical strength of clinched joints were analyzed using a FE model. The results showed that the defined parameter RC greatly increased the strength with the use of the EAMC process, which came with a reduction in forming load.