Asymmetric rolling of thin AA-5182 sheets: Modelling and experiments

The fundamental objective of the present work consists of the improvement of the plastic strain ratio (R-values) of AA-5182 aluminium alloy through improving the crystallographic texture by asymmetric rolling (ASR). The ASR process imposes intense shear deformation across the thickness of the sheet samples, leading to shear texture development. Finite element (FE) simulations of the ASR were first performed in order to investigate the impact of process parameters on the onset and growth of shear deformation throughout the thickness of sheet samples. In the present work, polycrystal simulations were also done to predict the texture evolutions and the mechanical response of the sheets deformed by different rolling processes. Afterwards, experimental studies were conducted. Conventional rolling (CR) as well as two types of ASR processes was carried out to reduce the thickness of the sheet samples. After each process, the rolled sheet samples were annealed. The crystallographic textures achieved in CR and ASR processes and annealing were measured. Furthermore, uniaxial tensile tests on the rolled sheets were also carried out in order to consider the effects of crystallographic texture on the macroscopic anisotropy. In agreement with the FE predictions, the experimental results showed that the shear strain spreads throughout the thickness of sheet samples during ASR and develops the shear texture. The mechanical behaviour and texture evolution predicted by numerical models are in good agreement with the experimental results. The modified texture leads to an increase of normal anisotropy as well as an increase of absolute value of planar anisotropy.