Effect of Different Aging Processes on the Microstructure and Mechanical Properties of a Novel Al-Cu-Li Alloy

The effects of different aging processes on the microstructure and mechanical properties of a novel Al-Cu-Li alloy have been investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. It is found that the tensile properties of a novel Al-Cu-Li alloy are sensitive to aging processes, which correspond to different microstructures. sigma (Al5Cu6Mg2) and T-1 (Al2CuLi) phases are the major precipitates for the alloy in T6 aging condition (165 degrees C/60 h). After duplex aging condition (150 degrees C/24 h + 180 degrees C/12 h), sigma, theta' (Al2Cu) and T-1 phases are detected. Only the T-1 phases can be found in the T8 state alloy (6% pre-strain+135 degrees C/60 h). The failure modes of alloy in T6 and duplex aging conditions are dimple-intergranular fracture, while typical quasi-cleavage fracture in T8 condition. Copyright (C) 2016, The editorial office of Journal of Materials Science & Technology. Published by Elsevier Limited.