Ultrafine-grained AA6014/AA5754 laminates produced by accumulative roll bonding (ARB)

Laminates with alternating AA6014 and AA5754 layers are produced by accumulative roll bonding (ARB). Depending on the number of ARB cycles the microstructure and the mechanical properties are investigated. The microstructure is characterized by scanning electron microscopy and correlated to the local mechanical properties determined by nanoindentation experiments. The overall properties are derived by tensile testing. The ultrafine-grained microstructure and the local mechanical properties alter with the layer composition. With increasing number of ARB cycles a much higher grain refinement is achieved within the AA5754 layers than in the AA6014 layers. The hardness of the individual layers develops similarly. On the macroscopic scale it is shown that the laminates are unifying the desired properties of the materials involved: high strength by a simultaneous suppression of the Portevin-Le Chatelier effect, typically occurring in the AA5754 alloy.