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

Hongying Li^1,2，Desheng Huang¹，Wei Kang¹，Jiaojiao Liu¹，Yangxun Ou¹，Dewang Li¹

1. School of Materials Science and Engineering, Central South University2. Key Laboratory of Non-ferrous Materials, Ministry of Education, Central South University

摘 要：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. σ（Al₅Cu₆Mg₂） and T₁（Al₂CuLi） phases are the major precipitates for the alloy in T6 aging condition（165 ℃/60 h）. After duplex aging condition（150 ℃/24 h + 180 ℃/12 h）, σ, θ’（Al₂Cu） and T₁ phases are detected. Only the T₁ phases can be found in the T8 state alloy（6% pre-strain+135 ℃/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.

关键词：