Patent ID: 8088234

Claim:
A method of manufacturing a wrought aluminum alloy product of an AA2000-series alloy, the method comprising the steps of: a. casting stock of an ingot of an AA2000-series aluminum alloy; b. preheating and/or homogenising the cast stock at a temperature in a range of 430 to 500° C.; c. heat treating the cast stock at a temperature in a range of more than 505° C. but lower than the solidus temperature of the subject aluminum alloy; d. hot working the stock by one or more methods selected from the group consisting of rolling, extrusion, and forging; e. optionally cold working the hot worked stock; f. first solution heat treating (SHT) of the hot worked and optionally cold worked stock; g. second solution heat treating of the worked stock at a higher temperature than the first SHT, the temperature being in a range of more than 505° C. but lower than the solidus temperature of the subject aluminium alloy and then rapidly cooling the SHT stock; h. optionally stretching or compressing the SHT stock that has undergone the second solution heat treating and rapid cooling or otherwise cold working the SHT stock that has undergone the second solution heat treating and rapid cooling to relieve stresses by at least one cold working step selected from the group consisting of levelling or drawing or cold rolling of the SHT stock that has undergone the second solution heat treating and rapid cooling; i. ageing of the cooled and optionally stretched or compressed or otherwise cold worked SHT stock to achieve a desired temper; wherein the heat treatment after the homogenisation heat treatment prior to hot working and the second solution heat treatment after the first solution heat treatment each has a soaking time of from about one to about 50 hours, and wherein the AA2000-series aluminum alloy product has a composition within the range of an aluminum alloy product selected from the group consisting of AA2324 with the proviso that the Si content is in a range of >0.10 to 0.35%, such that the alloy composition consists of, in wt. %: Cu 3.8-4.4 Mn 0.30-0.9 Mg 1.2-1.8 Cr max. 0.10 Zn max. 0.25 Ti max. 0.15 Si >0.10 to 0.35 Fe max. 0.12, incidental elements and impurities, each <0.05, total <0.15, balance aluminium, and AA2524 with the proviso that the Si content is in a range of >0.10 to 0.35%, such that the alloy composition consists of, in wt. %: Cu 4.0-4.5 Mn 0.45-0.7 Mg 1.2-1.6 Cr max. 0.05 Zn max. 0.15 Ti max. 0.1 Si >0.10 to 0.35 Fe max. 0.12, incidental elements and impurities each <0.05, total <0.15, balance aluminium.