2XXX SERIES ALUMINUM LITHIUM ALLOYS Russian patent published in 2018 - IPC C22C21/12 

FIELD: alloys.

SUBSTANCE: invention relates to 2xxx series aluminium-lithium alloys. Product made of a deformed aluminium alloy containing, wt%: 3.5-4.4 Cu, 0.45-0.75 Mg, 0.45-0.75 Zn, wherein (wt% Zn)/(wt% Mg) is 0.60-1.67, 0.65-1.000 Li, 0.1-1.0 Ag, from 0.05 to 0.50 at least one grain structure control element selected from the group consisting of Zr, Sc, Cr, V, Hf, rare earth elements and combinations of said elements, to 1.0 Mn, to 0.15 Ti, to 0.12 Si, to 0.15 Fe, to 0,05 any other element with a total content of said elements of not more than 0.15, and the balance is aluminium, has a thickness of at least 12.7 mm, and the fracture toughness for planar deformation (K_Ic) at least 22 ksi·√in.

EFFECT: invention is aimed at obtaining 2xxx series alloys with a combination of strength and viscosity, which make it possible to obtain higher resistance to stress corrosion cracking.

51 cl, 2 ex, 10 tbl, 3 dwg