The bendability of AA1200/AA2124 laminate sheets produced via Fusion™ technology

The Direct Chill Casting Fusion™ is a method of producing clad sheet cost effectively. In this paper some initial results are reported on a laminate sheet consisting of AA1200 on the clad surface and AA2124 as the core alloy. The clad alloy, AA1200, has a much lower strength and higher ductility than the core alloy, AA2124. In this work the microstructure of this laminate package and its bendability at various gauges were investigated. It has been demonstrated that the more ductile clad layer, which has a larger fracture strain level than that of the core alloy, delays the onset of surface cracking during bending and thus achieves a higher bending angle prior to failure. This is attributed to the small number of intermetallic particles in the cladding to assist in the nucleation and propagation of cracks at the higher strain outside bend surface. The clad alloy releases strain by necking when a crack is initiated - typically near the clad-core interface; thus preventing the crack from quickly propagating to the outer surface. © 2011 IBF (RWTH Aachen) & IUL (TU Dortmund).