ALUMINIUM-COPPER-LITHIUM SHEET WITH HIGH CRACK RESISTANCE FOR AIRCRAFT FUSELAGE Russian patent published in 2011 - IPC C22C21/16 C22F1/57 

FIELD: metallurgy.

SUBSTANCE: procedure for fabrication of sheet consists in preparing metal melt on base of aluminium, in casting plate, in homogenisation at temperature in interval from 490 to 530°C during 5-60 hours, in rolling said plate into sheet to finish thickness within range from 0.8 to 12 mm, in treatment in solution and in quenching, in controlled stretching said sheet with residual deformation from 1 to 5 %, and in tempering at heating from 140 to 170°C during 5-30 hours. Said melt on base of aluminium contains from 3.0 to 3.4 % in weight Cu, from 0.8 to 1.2 % in weight Li, from 0.2 to 0.5 % in weight Ag, from 0.2 to 0.6 % in weight Mg and at least one element chosen from Zr, Mn, Cr, Sc, Hf and Ti. Also, amount of the said, if chosen, element is from 0.05 to 0.13 % in weight for Zr, from 0.05 to 0.8 % in weight for Mn, from 0.05 to 0.3 % in weight for Cr and for Sc, from 0.05 to 0.5 % in weight for Hf and from 0.05 to 0.15 % in weight Ti, aluminium and unavoidable impurities - the rest. Contents of Cu and Li corresponds to ratio Cu (% in weight) + 5/3Li (% in weight) < 5.2.

EFFECT: production of sheet on base of aluminium possessing high mechanical strength, high crack resistance, high expansion of crack before unstable fracture and high corrosion resistance.

23 cl, 5 dwg, 16 tbl, 5 ex