Influence of Pre-deformation on Aging Precipitation Behavior of Three Al–Cu–Li Alloys

Jin-Feng Li¹，Zhi-Hao Ye¹，Dan-Yang Liu¹，Yong-Lai Chen²，Xu-Hu Zhang²，Xiu-Zhi Xu²，Zi-Qiao Zheng¹

1. School of Materials Science and Engineering,Central South University2. Aerospace Research Institute of Materials and Processing Technology

摘 要：The influence of pre-deformation on aging precipitates of three near peak-aged Al–Cu–Li alloys,1460 alloy with a low Cu/Li ratio（1.46）,2050 alloy with a high Cu/Li ratio（4.51） and 2A96 alloy with a medium Cu/Li ratio（2.97）,was investigated.The strength of the aged alloys is enhanced by the pre-deformation.The effectiveness of pre-deformation on precipitates is dependent on the alloy’s composition.With increasing the pre-deformation,the population density of T1（Al₂Cu Li） precipitates increases in all three Al–Cu–Li alloys and their diameter decreases in 2050 and 2A96 alloys,and the greatest effectiveness is observed in 2A96 alloy.The pre-deformation also increases the population density of θ’（Al₂Cu）precipitates and decreases their diameter in 2050 and 2A96 Al–Li alloys,but the effectiveness is smaller compared to that on T1 precipitates.In 1460 alloy subjected to two-step aging at 130 °C for 20 h followed by 160 °C for 12 h,the main precipitates are δ’（Al₃Li）.At 2%–6% pre-deformation,GP-I zones form and pre-deformation displays little influence.Eight percentage pre-deformation promotes θ’’/θ’ precipitation and increases their population density.

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