Self-Piercing Riveting of High-Ductility Al–Zn–Mg Casting Alloy (Nemalloy HE700) in F Temper

Abstract.Nemalloy HE700 (high elongation) automotive Al alloy, a newly developed Al–Fe hypoeutectic-based alloy for high-vacuum high-pressure die casting, provides higher strength and elongation even without heat treatment compared to current mainstream structural automotive Al casting alloy. This study aims to systematically investigate the application of HE700 in the field of self-piercing riveting (SPR): the joinability of HE700 castings with dissimilar materials, directed by automotive industry standards. Several rounds of exploratory experiments amply showed the feasibility of obtaining valid SPR joints of HE700 castings (2.5 mm thick) with Al 6082 alloy (2.5 mm) and DP600 steel (1.2 mm) sheets with acceptable automotive quality standards. The influence of the die shape, rivet geometry and maximum punch force were the critical process parameters investigated. Finally, this article endorsed the viability of significant automotive lightweighting with a lower carbon footprint while integrating novel casting alloys such as HE700 into the automotive superstructure through economical joining processes such as SPR.