High Lightweight Potential of Ultrafine-Grained Aluminum/Steel Laminated Metal Composites Produced by Accumulative Roll Bonding

The focus of this paper is the designing of ultrafine-grained aluminum/steel laminated metal composites for innovative lightweight materials concepts used for cyclic loading. These ultrafine-grained composites are produced by the accumulative roll bonding process. Three different aluminum/steel composites are studied, where the position of the steel layers is varied, to investigate the influence of the layer architecture. The mechanical properties are measured in monotonic and cyclic three-point bending tests. The influence of the meso- and microstructure are intensively studied by scanning electron microscope observations. Furthermore, the internal stresses during elastic straining are calculated by a finite element simulation. In the composites, both monotonic and cyclic mechanical properties are strongly increased and are clearly higher as expected by a linear rule of mixtures of the constituent materials. This increase is particularly high for the fatigue properties resulting in a strongly enhanced specific fatigue limit of the composites.