Effects of Deformation Texture Intensities and Precipitates on the Anisotropy of Mechanical Properties of Al-Li Alloy 2099 T83 Extrusions

Abstract

The use of aluminum-lithium alloys in aerospace applications requires a thorough knowledge of how processing and product geometry impact their microstructure, texture and mechanical properties. As with other aluminum alloys, anisotropy of mechanical properties has been related to the formation of deformation textures during thermo-mechanical processes. Static mechanical properties and microstructural characteristics such as texture and precipitate distribution were analysed in two series of 2099-T83 extrusions, i.e. a cylindrical extrusion and an integrally stiffened panel (ISP). The cylindrical extrusions present <111> and <100> fiber textures while the ISP possesses the same fiber textures with lower intensities. Rolling textures such as Brass were also observed in some locations of the ISP. The levels of longitudinal strength and static anisotropy correlate well with the intensity of the fiber texture. Moreover, varying densities of T-1 (Al2CuLi) precipitates were observed in the TEM.