7XXX ALUMINUM ALLOYS
New 7xxx aluminum alloys are disclosed. The new 7xxx aluminum alloys generally include from 0.05 to 1.0 wt. % Ag. In one approach, a new 7xxx aluminum alloy includes from 0.05 to 1.0 wt. % Ag, from 5.5 to 9.0 wt. % Zn, from 1.2 to 2.6 wt. % Cu, from 1.3 to 2.5 wt. % Mg, up to 0.60 wt. % Mn, up to 1.0 wt. % of at least one grain structure control material, wherein the at least one grain structure control material is selected from the group consisting of Zr, Cr, V, Hf, other rare earth elements, and combinations thereof, up to 0.30 wt. % Fe, up to 0.30 wt. % Si, up to 0.15 wt. % Ti, not greater than 0.08 wt. % Sc, and not greater than 0.05 wt. % Li, the balance being aluminum, optional incidental elements and impurities.
1 . A wrought 7xxx aluminum alloy product, wherein the wrought 7xxx aluminum alloy product comprises:
from 0.05 to 1.0 wt. % Ag;
from 1.2 to 2.6 wt. % Cu;
from 1.3 to 2.5 wt. % Mg;
from 5.5 to 9.0 wt. % Zn;
up to 0.60 wt. % Mn;
up to 1.0 wt. % of at least one grain structure control material, wherein the at least one grain structure control material is selected from the group consisting of Zr, Cr, V, Hf, other rare earth elements, and combinations thereof,
up to 0.30 wt. % Fe;
up to 0.30 wt. % Si;
up to 0.15 wt. % Ti;
not greater than 0.08 wt. % Sc;
not greater than 0.05 wt. % Li;
the balance being aluminum, optional incidental elements and impurities;
wherein the wrought 7xxx aluminum alloy product has a thickness of from 12.7 to 305 mm.
2 . The wrought 7xxx aluminum alloy product of claim 1 , wherein the 7xxx aluminum alloy comprises from 6.0 to 8.5 wt. % Zn.
3 . The wrought 7xxx aluminum alloy product of claim 2 , wherein the 7xxx aluminum alloy comprises from 1.5 to 2.0 wt. % Cu.
4 . The wrought 7xxx aluminum alloy product of claim 3 , wherein the 7xxx aluminum alloy comprises from 1.4 to 2.0 wt. % Mg.
5 . The wrought 7xxx aluminum alloy product of claim 1 , wherein (wt. % Cu)+(wt. % Mg)≥3.0 wt. %.
6 . The wrought 7xxx aluminum alloy product of claim 1 , wherein the 7xxx aluminum alloy comprises at least 0.10 wt. % Ag.
7 . The wrought 7xxx aluminum alloy product of claim 1 , wherein the 7xxx aluminum alloy comprises not greater than 0.7 wt. % Ag.
8 . The wrought 7xxx aluminum alloy product of claim 1 , wherein the 7xxx aluminum alloy comprises from 0.10 to 0.50 wt. % Mn.
9 . The wrought 7xxx aluminum alloy product of claim 1 , wherein the 7xxx aluminum alloy comprises not greater than 0.01 wt. % Mn.
10 . The wrought 7xxx aluminum alloy product of claim 1 , wherein the at least one grain structure control material is at least chromium, and wherein the 7xxx aluminum alloy comprises from 0.05 to 0.24 wt. % Cr.
11 . The wrought 7xxx aluminum alloy product of claim 1 , wherein the 7xxx aluminum alloy comprises not greater than 0.01 wt. % Cr.
12 . The wrought 7xxx aluminum alloy product of claim 1 , wherein the 7xxx aluminum alloy includes from 0.010 to 0.10 wt. % Ti.
13 . The wrought 7xxx aluminum alloy product of claim 1 , wherein the grain structure control material is at least Zr, and wherein the alloy includes 0.05 to 0.20 wt. % Zr.
14 . The wrought 7xxx aluminum alloy product of claim 1 , wherein the wrought aluminum alloy product realizes a typical tensile yield strength (ST) of at least 400 MPa in a T7 temper.
15 . The wrought 7xxx aluminum alloy product of claim 14 , wherein the wrought aluminum alloy product realizes a plane-strain (K IC ) fracture toughness (S-L) of at least 20 MPa-sqrt-m in a T7 temper.
16 . The wrought 7xxx aluminum alloy product of claim 15 , wherein the wrought aluminum alloy product realizes an elongation (ST) of at least 2.0% in a T7 temper.
17 . The wrought 7xxx aluminum alloy product of claim 16 , wherein the wrought aluminum alloy product passes HHSCC-G49 testing at 70° C. at 100 days or at 90° C. for 10 days.
18 . The wrought 7xxx aluminum alloy product of claim 17 , wherein the wrought aluminum alloy product passes SCC alternate immersion testing at 20 days and a net stress (ST) of 172 MPa.
19 . The wrought 7xxx aluminum alloy product of claim 18 , wherein the wrought aluminum alloy product passes HHSCC-G168, wherein the stress intensity factor gives a crack growth rate of not greater than 10 −7 mm/s, and wherein the realized K value is at least 13 MPa-sqrt-m (MPa√m).