Laminated metallic composites (LMCs) produced by accumulative roll bonding (ARB) offer a new way for light-weight materials design by tailoring and grading materials properties. The used ARB process to produce the LMCs allows to combine a wide range of different materials. The ARB process also leads to an ultrafine grained microstructure resulting in a significantly higher strength of the materials. In that course, the properties are also affected by the layer sequence and the layer thickness. In this context, the impact of the number of interfaces, of the layer thickness and the material combination on the mechanical behavior is almost unclear.
In this study the influence of the stacking sequence of LMCs on the mechanical properties was investigated. The copper alloy CuSn0.15 and the aluminum alloy AA5754 were roll bonded at room temperature and constant layer thicknesses without fragmentation have been achieved. In order to investigate the influences of stacking sequence on the mechanical behavior, the outer layer of the metal sheets was alternated between Al and Cu. Thus, two stacking sequences have been investigated, one with aluminum on the outside and one with copper on the outside. Ex- and in-situ investigations in a Large-Chamber SEM reveal different mechanical behavior of the two sheet designs. Especially 3 point bending fatigue tests show different behavior in crack initiation and propagation. Also the crack transition from one into the other material is of great interest and was investigated in these in-situ fatigue tests. The different Young’s moduli and the strain rate sensitivity are found to influence the materials properties. Digital image correlation was used in in-situ tensile tests in the Large-Chamber SEM to visualize differences in the deformation behavior between the two designs.