ALUMINUM BASE ALLOY AND ITS HEAT TREATMENT METHOD Russian patent published in 2007 - IPC C22C21/06 C22F1/47 

FIELD: metallurgy of aluminum base alloys such as Al-Mg-Li-Cu system alloys used as constructional materials in aircraft making and spatial technology, transport machine engineering for making facing and inner reinforcing structures.

SUBSTANCE: alloy contains next ingredients, mass %: lithium, 1.5 - 1.9; magnesium, 1.2 - 3.5; copper, 1.4 - 1.8; zinc, 0.01 -1.2; manganese, 0,01 - 0.8; titanium, 0.01 -0.25; silicon, 0.005- 0.8; cerium, 0.005 -0.4; at least one element selected from group including scandium, 0.01 - 0.3; zirconium, 0.003 - 0,15; beryllium, 0.001 - 0.2; aluminum, the balance. Method for heat treatment of alloy comprises steps of quenching, straightening and artificial aging according to three-step mode. Quenching is performed from temperature 510 - 535°C. First step of artificial aging is realized at temperature 95 - 120°C. In concrete variants of invention second step of aging is realized at temperature 130 -180°C for 3 - 25 hours. Third step of artificial aging is realized at temperature 95 - 120°C for time period 15 h and more. Invention provides enhanced strength and thermal stability of alloy after heating at 85°C for 100 h while keeping high viscosity of rupture and technological plasticity of alloy at making thin sheets by coil rolling.

EFFECT: improved strength and thermal stability of alloy.

3 cl, 4 tbl, 1 ex