METHOD OF THERMOMECHANICAL TREATMENT OF SEMI-FINISHED PRODUCTS MADE FROM ALUMINUM ALLOYS Russian patent published in 2005 - IPC

FIELD: metallurgy of aluminum-based alloys, alloys of Al-Mg-Li inclusive; manufacture of thin-walled semi-finished products for stringer and load-bearing primary structure of fuselage in riveted and welded structural members.

SUBSTANCE: proposed method includes hot deformation and hardening performed at one heat and followed by cold plastic deformation. Hot deformation is performed at degree not less than 82%; then cooling in air performed at rate of 0.3-10°C/s; cold plastic deformation is performed at degree not exceeding 4%. In specific cases, hot deformation and hardening may be performed at one heat at temperature of 380-480°C; after cold plastic deformation, one- or three-stage artificial aging is performed; at one-stage aging, heating is performed at 115-125°C and holding is continued for 5-12 h; at three-stage aging, heating at first stage is performed at 80-90°C and at holding continued for 3-6 h; at second stage, heating is performed at 115-125°C and at holding continued for 10-16 h; at third stage, heating is performed at 95-105°C and at holding continued for 10-12 h.

EFFECT: improved strength, plasticity and corrosion resistance characteristics.

5 cl, 2 tbl, 1 ex