Microstructural evolution and mechanical properties of multilayered ARB6/3/6 2N Al processed by accumulative roll bonding

The multilayered 2N (99.2% purity) Al sheets containing 3-cycle ARB processed layers (shorted as ARB3 layer) with low strain and 6-cycle ARB processed layers (shorted as ARB6 layer) with high strain were prepared by accumulative roll bonding (ARB) process. The multilayered 2N Al (referred as ARB6/3/6 Al) sheets were further annealed at various temperatures. The effect of annealing process on the microstructures and mechanical properties of the multilayered ARB6/3/6 Al were systematically studied and compared with a conventional ARB6 2N Al. Recrystallized grains and grains coarsening are more pronounced in ARB6 layers comparing with the ARB3 layers due to high total strain in ARB6 layers. The ultimate tensile strength and uniform elongation of ARB6/3/6 are 219 MPa and 2.4%, respectively. Both decreasing trends of normalized strength are almost similar in ARB6 Al and ARB6/3/6 Al after annealing, while the elongation in ARB6/3/6 Al recover more rapidly than ARB6 2N Al due to the suppression of the early necking.