摘要
In this work, the microstructure and precipitation phases were primarily characterized by transmission electron microscopy. The mechanical properties were evaluated by tensile and tear test. The results indicated that the samples aged at 145 ℃ for 45 h or 155 ℃ for 30 h possessed a preferable combination of strength and plasticity, owing to the precipitation of well-dispersed T1 （A12CuLi） phases （diameter 〈 150 nm）. However, aging at more than 165 ℃ caused an obvious size growth of T1 plates, leading to the quick reduction in plasticity and toughness. Furthermore, the high Cu/Li ratio resulted in distinct precipitation features, including a shorter incubation time of T1 phase and the aggravated precipitate-free zones.
In this work, the microstructure and precipitation phases were primarily characterized by transmission electron microscopy. The mechanical properties were evaluated by tensile and tear test. The results indicated that the samples aged at 145 ℃ for 45 h or 155 ℃ for 30 h possessed a preferable combination of strength and plasticity, owing to the precipitation of well-dispersed T1 （A12CuLi） phases （diameter 〈 150 nm）. However, aging at more than 165 ℃ caused an obvious size growth of T1 plates, leading to the quick reduction in plasticity and toughness. Furthermore, the high Cu/Li ratio resulted in distinct precipitation features, including a shorter incubation time of T1 phase and the aggravated precipitate-free zones.
基金
the financial support of the Fund of National Engineering and Research Center for Commercial Aircraft Manufacturing (No. SAMC13-JS-15-032)
Jiangsu Innovation Program for Graduate Education (No. KYLX0259)
the Fundamental Research Funds for the Central Universities
the Foundation of Graduate Innovation Center in NUAA(No. kfjj20130220)
Opening Project of Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology (No. ASMA201401)
