High strength forged aluminum alloy products
View Patent ↗High strength forged aluminum alloys and methods for producing the same are disclosed. The forged aluminum alloy products may have grains having a high aspect ratio in at least two planes, generally the L-ST and the LT-ST planes. The forged aluminum alloy products may also have a high amount of texture. The forged products may realize increased strength relative to conventionally prepared forged products of comparable product form, composition and temper.
1. A method comprising:
(a) extruding a 2xxx aluminum alloy into an extruded product;
(i) wherein the extruding comprises an extrusion ratio of from 7:1 to 50:1;
(ii) wherein the extruded product has a thickness of at least 2 inches;
(b) forging the extruded product into a forged product, wherein the forging comprises:
(i) hot working the extruded product into the forged product using a hydraulic press, and such that the forged product realizes a crystalline microstructure having from 5 vol. % to 50 vol.% of a first type grains,
(i) wherein the first type grains include representative first grains;
(ii) wherein the representative first grains make up 60-90 vol. % of the first type grains;
(iii) wherein the representative first grains have an average aspect ratio of from 5:1 to 20:1 in the LT-ST plane;
(iv) wherein the representative first grains have an average aspect ratio of from 6: 1 to 30:1 in the L-ST plane;
(v) wherein at least portions of the forged product have a sectional thickness of at least 1 inch.
2. The method of claim 1 , wherein the extruding step uses indirect extrusion.
3. The method of claim 2 , wherein the extruding step (a) comprises induction heating.
4. The method of claim 3 , wherein the extruding step comprises controlling temperature during the extruding step to +/−15°F.
5. The method of claim 3 , wherein the extruding comprises adiabatic extrusion.
6. The method of claim 3 , wherein the forging step (b) comprises forging with the hydraulic press at a rate of from 10 to 30 inches per minute ram speed.
7. The method of claim 6 , wherein the forging comprises forging at a forging temperature; and
wherein, during the forging step, the forging temperature is within 45° F. of an incipient melting temperature of the aluminum alloy, and wherein the forging temperature is below the incipient melting temperature of the aluminum alloy.
8. The method of claim 7 , wherein the forging temperature is controlled to +/−20° F. during the forging step.
9. The method of claim 1 , wherein the method comprises, after the solution heat treating and quenching step:
artificially aging the forged product to one of a T6 or a T8 temper.
10. The method of claim 1 , wherein the 2xxx aluminum alloy is a 2xxx+Li aluminum alloy.
11. The method of claim 10 , wherein the 2xxx+Li alloy contains up to 2 wt. % Li.
12. The method of claim 1 , wherein the 2xxx aluminum alloy is selected from the group consisting of 2x24, 2040, 2139, 2219, 2195, and 2050.
13. The method of claim 1 , wherein the 2xxx aluminum alloy includes 2-6 wt. % Cu and 0.1-1 wt. % Mg, optionally with up to 2 wt. % Li, up to 1 wt. % Mn, and up to 1 wt. % Ag.