Influence of the rolling direction on the microstructure, mechanical, anisotropy and gamma rays shielding properties of an Al-Cu-Li-Mg-X alloy

The impact of different rolling orientations (0°, 45° and 90°) on the microstructure, mechanical, in-plane anisotropy (IPA) and gamma rays (γ-rays) shielding properties of a lately developed Al-Cu-Li-Mg-X (X = Mn, Zr, Zn) alloy was investigated. The results showed that rolling along several directions corresponded to distinctive microstructures, which considerably affected the properties. The main strengthening phases in the alloy were δ'(Al3Li), Al3(Zr,Li) and T1(Al2CuLi), while the strengthening effect of the T1 precipitates was predominant. The main precipitates were δ'(Al3Li), minor Al3(Zr,Li) and coarse T1(Al2CuLi) phases when rolled along the 0° direction, a large amount of fine T1(Al2CuLi) phase with few δ'(Al3Li) and Al3(Zr,Li) precipitates by rolling along the 45°direction, besides, a large amount of the Al3(Zr,Li) phase with minor δ'(Al3Li) in the alloy rolled along the 90° direction. The alloy rolled along the 90° orientation exhibited the appropriate isotropic mechanical behavior, which was caused by the homogeneously distributed dislocations that produced a homogeneous dispersion of the strengthening precipitates in the three tensile angles. In addition, the shielding property showed different screening ratios when varying the rolling direction. The 90° rolling direction presented the most desirable shielding property.