Abstract: The influences of Cu and Mg on the microstructure and properties of rapidly solidified Al(3-4 wt% )Li alloys prepared by atomization technique have been studied in the present investigation.The results showed that additions of Cu and Mg in high lithium content RS Al-Li alloys are limited due to the formation of coarse intermetallics during solution treatment. With certain addition of Cu,Mg and conventional heat treatment, the Cu and Mg containing phase S(Al_2CuMg)was found to co-precipitate with δ' (Al_3Li) in the alloys. However the acceptable combinations of strength and ductility of the alloy could not be acquired. Optimizations of Cu and Mg content added in high lithium RS Al-Li alloys are given and the reasons are discussed in detail.

Key words: Al-Li alloy, microstructure and pruperty, rapid solidification