METHOD OF MANUFACTURING INTERMEDIATE PRODUCTS FROM ALUMINUM ALLOY, AND ARTICLE OBTAINED BY THIS METHOD Russian patent published in 2004 - IPC

FIELD: nonferrous metallurgy.

SUBSTANCE: invention relates to metallurgy of aluminum alloys, in particular to those containing lithium and copper employed in the form of rolled, pressed, and forged intermediate products for manufacturing load-bearing elements of riveted and welded structures from the field of aircraft and space engineering. Method of invention comprises casting ingots, homogenization, hot deformation at 250-470^оС, intermediate annealing, cold deformation, heat treatment into solid solution, hardening and ageing at 100-200^оС. Homogenization of ingots is effected in two steps, employing in the first step heating at temperature by 20-60^оС and in the second step by 95-120^оС higher than temperature T_x, while intermediate annealing in hot deformation operation is effected at temperature by 80-140^оС higher than temperature T_y and heat treatment into solid solution effected at temperature by 65-140^оС higher than temperature T_x, where T_x is temperature of minimal stability of solid solution in the region of existence of phase T₂(Al₆CuLi₃) and T_y is temperature of minimal stability of solid solution in the region of existence of phase T₁(Al₂CuLi). In particular embodiments of invention, hot, cold deformation, and intermediate annealing are accomplished in one or more steps and hardening is effected at velocity ≥3.5 V_crit wherein V_crit denotes critical hardening velocity.

EFFECT: enabled manufacture of intermediate products with elevated plasticity and high corrosion resistance, fracture resistance, and cyclic crack growth resistance characteristics.

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