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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 °C for 45 h or 155 °C for 30 h possessed a preferable combination of strength and plasticity, owing to the precipitation of well-dispersed T1(Al2Cu Li) phases(diameter 150 nm). However, aging at more than 165 °C 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.
The results showed that the samples aged at 145 ° C for 45 h or 155 ° C for 30 h possessed due to the precipitation of well-dispersed T1 (Al2Cu Li) phases (diameter 150 nm). However, aging at more than 165 ° C 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.