Abstract:Based on 18 Al-Li alloys with various Cu (3. 24% ~ 4. 16%) and Li (0. 94% ~ 1. 44%) con鄄
tents, the influence of Cu and Li contents on the mechanical properties and microstructures of T8 aged Al-Li alloys
with micro鄄alloying elements of 0. 4Mg, 0. 4Ag and 0. 4Zn was investigated. The strengthening effect and microstruc鄄
ture variation were analyzed through total non鄄solution atomic fraction of Cu and Li and their atomic ratio. The
strengthening precipitates consisted of T1(Al2CuLi), q忆(Al2Cu) and d忆(Al3Li). With increasing the total non鄄solu鄄
tion atomic fraction of Cu and Li and their atomic ratio, the total amounts of precipitates and the proportion of T1 pre鄄
cipitates were increased, the alloy strength was enhanced. Lower Cu/ Li atomic ratio led to an increase in d忆precipi鄄
tates, and therefore lowered the alloy strength.
