Microstructure, texture and mechanical properties of sandwiched ARB6/2/6 2N Al fabricated by accumulative roll bonding

Two-cycle accumulative roll bonding (ARB) process was applied to produce sandwiched 2N-Al (99.2% purity) sheets (referred as ARB6/ARB2/ARB6) initially containing 2-cycle ARB processed core-layers (shorted as ARB2 layer) with coarse grains and 6-cycle ARB processed outer-layers (shorted as ARB6 layer) with fine grains. The ARB6/ARB2/ARB6 (shorted as ARB6/2/6) sheets were further annealed at various temperatures. The effect of annealing process on the microstructures and mechanical properties of the sandwiched samples were systematically studied and compared with a conventional 6-cycle ARB processed 2N Al sample (shorted as ARB6). The grain size in the ARB2 layer is larger than that in the ARB6 layers in ARB6/2/6 due to the lower strain in the ARB2 layer. During annealing, the grain growth rate in the ARB6 layers is faster than that of the ARB2 layer. The ultimate tensile strength and uniform elongation of ARB6/2/6 are 219 MPa and 2.4%, respectively. It is found that ARB6/2/6 have similar normalized strengths to ARB6, but the normalized elongation of ARB6/2/6 is much larger than those of ARB6, which is in consistent with other materials with heterogeneous structures.

Automated summary

The study utilized a two-cycle accumulative roll bonding process to produce sandwiched 2N-Al sheets, and systematically investigated the microstructures and mechanical properties of the samples after annealing. It was found that the ARB6/2/6 samples exhibited good performance in terms of ultimate tensile strength and uniform elongation.