Joining Aluminium Alloys with Reduced Ductility by Mechanical Clinching

The joinability of aluminium alloy sheets with reduced ductility produced by mechanical clinching is analyzed. A modified tool set geometry was developed to reduce the localization and magnitude of plastic strain. Sheets preheating was adopted to increase the material formability. Optical microscopy and scanning electron microscopy were utilized to observe possible presence of cracks in clinched connections and to perform dimensional analysis. Mechanical characterization tests comprising micro-hardness test and single lap shear tests were conducted to evaluate the influence of the processing conditions on joints strength.