Patent ID: 8088234
Filing Date: 2012-01-03
Classification: C22C,C22F

Abstract:
1. 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; incidental elements and impurities, each <0.05, total <0.15, balance aluminium, and incidental elements and impurities each <0.05, total <0.15, balance aluminium.