Aa7000-series aluminum alloy products and a method of manufacturing thereof
AssigneeAleris Aluminum Koblenz GmbH
InventorsSunil Khosla, Andrew Norman, Hugo Van Schoonevelt
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Abstract
An AA7000-series alloy including 3 to 10% Zn, 1 to 3% Mg, at most 2.5% Cu, Fe <0.25%, and Si >0.12 to 0.35%, and a method of manufacturing these aluminum alloy products. More particularly, disclosed are aluminum wrought products in relatively thick gauges, in particular i.e. about 30 to 300 mm thick. While typically practiced on rolled plate product forms, this method may also find use with manufacturing extrusions or forged product shapes. Representative structural component parts made from the alloy product include integral spar members, and the like, which are machined from thick wrought sections, including rolled plate.
Claims50
A method of manufacturing a wrought aluminum alloy product of an AA7000-series alloy, the method comprising the steps of:
- a. casting stock of an ingot of an AA7000-series aluminum alloy having >0.12 to 0.35% Si;
- b. preheating and/or homogenizing the cast stock;
- c. hot working the stock by one or more methods selected from the group consisting of rolling, extrusion, and forging;
- d. optionally cold working the hot worked stock;
- e. solution heat treating (SHT) of the hot worked and optionally cold worked stock;
- f. cooling the SHT stock;
- g. optionally stretching or compressing the cooled SHT stock or otherwise cold working the cooled SHT stock to relieve stresses;
- h. ageing of the cooled and optionally stretched or compressed or otherwise cold worked SHT stock to achieve a desired temper, and wherein there is at least one heat treatment carried out at a temperature in a range of more than 500° C. but lower than the solidus temperature of the subject aluminum alloy, and wherein this heat treatment is carried out either:
- (i) after the homogenisation heat treatment prior to hot working, or (ii) after the solution heat treatment, or (iii) both after the homogenisation heat treatment prior to hot working and after the solution heat treatment.
An aluminum alloy wrought product which has been cast, preheated and/or homogenised, hot worked, optionally cold worked, solution heat treated, cooled, optionally stretched or compressed, and aged to a desired temper, and has been subjected to at least one heat treatment carried out at a temperature in a range of more than 500° C. but lower than the solidus temperature of the subject aluminum alloy, and wherein this heat treatment is carried out either:
- (i) after the homogenisation heat treatment prior to hot working, or (ii) after the solution heat treatment, or (iii) both after the homogenisation heat treatment prior to hot working and after the solution heat treatment, said alloy consisting essentially of, in wt. %:
- Zn
- about 3 to 10%
- Mg
- about 1 to 3%
- Cu
- 0 to 2.5%
- Fe
- <0.25%
- Si
- >0.12 to 0.35%,
- one or more elements selected from the group consisting of:
- Zr
- at most 0.5,
- Ti
- at most 0.3,
- Cr
- at most 0.4,
- Sc
- at most 0.5,
- Hf
- at most 0.3,
- Mn
- at most 0.4,
- V
- at most 0.4,
- Ag
- at most 0.5%,
- said alloy optionally containing at most:
- 0.05
- Ca,
- 0.05
- Sr,
- 0.004
- Be,
- balance being Al, incidental elements and impurities.
Dependencies are inferred from the claim text.