THERMAL HARDENING OF THE AGING ALUMINUM ALLOYS BY THE SECONDARY SEPARATION Russian patent published in 2007 - IPC C22F1/04 

FIELD: nonferrous metallurgy; methods of the thermal hardening of the aging aluminum alloys.

SUBSTANCE: the invention is pertaining to thermal treatment of the aging aluminum alloys suitable for hardening. The method includes three phases of the thermal treatment of such an aged alloy. At the first phase of the thermal treatment (a) they conduct the alloy curing at the heightened aging temperature, which facilitates the process of extraction of at least one dissolved element. The aging is conducted during the time span ensuring production of the non-aged alloy having no less than 40 % and no more than 85 % of the values of the maximal hardness and strength achieved at the complete treatment up to the state Т6. At the second phase conduct chilling of the non-aged alloy from the ageing temperature of the phase (a) to the much lower temperature from -10°С to 65°С. The chilling is conducted at the rather high speed with the purpose essentially to suspend primary extraction. At the third phase the cooled alloy is effected by the much lower ageing temperature, than the ageing temperature of the phase of (a) - for the further extraction of the dissolved element defined as «the secondary extraction». The technical result of the invention is the development of the method allowing to gain the improved combinations of mechanical properties.

EFFECT: the invention ensures development of the method allowing to gain the improved combinations of the aluminum alloy mechanical properties.

23 cl, 4 tbl, 15 dwg