Stability of supersaturated solid solution of aluminum-lithium alloy 1470

The prospects of the use of aluminum - lithium alloys in the aircraft industry are due to their diminished density and high rigidity as compared to the similar properties of alloys without lithium. This makes it possible to diminish considerably the mass of the structure, which greatly influences the fuel and weight efficiency of the product. The demand for such alloys in aircraft engineering grows steadily. The pioneer alloys of this kind belonged to the Al - Mg - Li system, then came Al - Cu - Li alloys, With the recent creation of alloys in the Al - Li - Cu - Mg system the application range of the alloys has widened substantially. Their main disadvantages include the low adaptability to manufacture and the tendency to embrittlement in the process of long-term operation at a temperature much above room temperature, for example, in solar heating. The present paper is devoted to the special features of the decomposition of the supersaturated solid solution in a new promising alloy 1470 (Al - Li - Mg - Cu) and the nature of the phases formed. The obtained results have been used for developing practical recommendations for the choice of regimes for reinforcing heat treatment of semiproducts from alloy 1470.