Abstract:The mechanical anisotropy and inhomogeneity through thickness of 2297-T87 aluminum alloy thick plate of 85 mm were investigated by tensile test, optical microscopy, X ray diffractometry, scanning electron microscopy(SEM) and transmission electron microscopy(TEM). The results show that the mechanical properties in L orientation is inhomogeneous in different layers along the thickness direction, that the strength increases from the surface to the center. The difference of LT orientation is not significant, however. Meanwhile the texture distributes nonuniformly through thickness. The centre of the plate is mainly β fiber texture and Goss texture, while besides deformation texture, the recrystallization texture is observed near the surface. In the T/8 layer, the fraction of the shear texture is maximum. The T/4 layer seems to serve as a transition layer, presenting a small amount of the recrystallization texture, shear texture and β fiber texture at the same time. At the same thickness, the anisotropy of mechanical properties is obvious. There is reasonable concordance between changes of the strength and plasticity: L>LT>ST. The anisotropy is associated with the grain structure and the second phase particles.