Investigation on Clinching with Additional Local Material Bond by Thermal Joining

Abstract

In the investigation, point-shaped connections were created by combining a clinching process with laser beam welding and resistance spot welding. The connection, which was generated, unites the form-fitting joint of clinching operations with the material bond of thermal joining processes. The objective was to use the advantages of both types of joints with respect to the mechanical properties. For joints made by clinching, these are high cyclic strengths. For joints made by welding, these are high static strengths. A sheet metal combination consisting of two EN AW-5754 sheets, each with a thickness of 1 mm, was assembled. In addition to the strengths under different load types, the respective failure behavior of the individual compounds was investigated. It is proven that the combination of the methods shows both a change in strengths and new failure mechanisms. In conclusion, it is presented that an increase in strength can be realized by additional local material bond of a clinched joint in the static case without causing a reduction in strength in the cyclic load case. Furthermore, it is shown that a local material bond at the undercut or outside a clinching joint has no increased notch effect through the thermal joining process, even though the material bond is only in the periphery of the clinching joint.