ALUMINUM ALLOY 7085
High Strength, High Toughness, Corrosion-Resistant Thick Plate
DESCRIPTION
APPLICATIONS
Alcoa developed aluminum alloy AA 7085 to provide combinations of higher strength and fracture toughness than legacy
7000-Series in thick sections. 7085 is based on a unique
composition optimized to provide low quench sensitivity.
The combination of high strength and fracture toughness
properties and corrosion resistance in thick sections makes
7085 suitable as a replacement for 7050 and other thick
product alloys for critical thick product applications included
but not limited to spar, rib, and integrally machined structural
parts for new, derivative, or retrofit aircraft.
Alloy 7085 plate is available in the T7451 temper from 3.0
to 7.0 inches (76.2 to 177.8 mm) thick and in the T7651
temper from 4.0 to 7.0 inches (101.6 to 177.8 mm) thick.
The corrosion resistance (exfoliation and stress corrosion
cracking resistance) of 7085 is comparable to that of legacy
7000-Series for a given temper.
COMMERCIAL STATUS
Alcoa alloy 7085 plate is covered by AMS 4329 (T7651
temper) and AMS 4470 (T7451 temper). Material design
allowables are available in MMPDS.
CHEMICAL COMPOSITION Chemical Composition Limits • AA 7085 (Wt.%)*
Zn
Cu
Mg
Zr
Mn
Cr
Ti
Si
Fe
Al
7.0-8.0
1.3-2.0
1.2-1.8
0.08-0.15
0.04 max
0.04 max
0.06 max
0.06 max
0.08 max
Remainder
*Other elements: 0.05 wt.% max (each); 0.15 wt.% max (total)
32
30
28
7050-T7451
AMS 4050
26
24
5-6"
22
5-6"
20
55
57
59
7085-T7451
AMS 4470
4-5"
6-7"
4-5"
5-6"
6-7"
4-5"
4-5"
5-6"
6-7"
4-5"
7085-T7651
AMS 4329
5-6"
3-4"
3-4"
4-5"
3-4"
61
7085-T7451, 4 in.
7085-T7451, 6 in.
7085-T7651, 4 in.
7050-T7451, 4 in.
7050-T7451, 6 in.
7050-T7651, 4 in.
1.E-03
63
65
6-7"
67
da/dN (in/cycle)
34
1.E-02
3-4"
7085-T7651 (L)
7085-T7651 (LT)
7085-T7451 (L)
7085-T7451 (LT)
7050-T7451 (L)
7050-T7451 (LT)
36
1.E-04
1.E-05
1.E-06
RH > 90%, Freq.= 25 Hz
T/4 Plane
5-6"
69
71
73
75
1.E-07
1
10
K (ksi in)
L or LT Tensile Yield Strength (A-basis,ksi)
7085-T7451, Smooth (Kt=1) Axial Fatigue, R=0.1
Lab Air (RH 33-42%), Freq.= 30 Hz
LT Orient., T/2 Plane
60
Runout
50
x4
40
x10 x3
7050-T7451 AMS 4050
30
1.E+04
1.E+05
Cycles, N
1.E+06
1.E+07
100
7085-T7651, Open Hole (Kt=2.3), R=0.1
50
7085-T7451, 6 lots, 4-7 in.
Maximum Net Stress, ksi
70
Maximum Stress, ksi
The following tables and figures
provide mechanical properties
for 7085 in the T7651 and T7451
tempers, and compare 7085
properties with 7050. Alloy 7085
plate offers superior strength and
fracture toughness with similar
fatigue and fatigue crack growth
resistance.
7085 Fatigue Crack Growth, T-L Orient., R=0.1
Strength - Toughness Minima for 7085 Plate
38
L-T or T-L KIc (S-basis, ksi in)
MECHANICAL
PROPERTIES
7085-T7651, 4 - 6 in. Plate, 6 lots
Runout
40
30
x5
20
High Humidity (RH>90%), Freq.= 25 Hz
L-T Orient., T/2 Plane
10
1.E+04
CONTACT AND PROCUREMENT
For additional information on 7085 plate, contact your local Alcoa Sales Account Manager.
1.E+05
1.E+06
Cycles, N
1.E+07
Static Properties • 7085 Plate • Minimum Values (S- or A-Basis)
Thickness
Inch (mm)
7085-T7651 (AMS 4329)
Direction
3.000-4.000
(76.20-101.60)
4.001-5.000
(101.62-127.00)
5.001-6.000
(127.02-152.40)
6.001-7.000
(152.42-177.80)
Fty (A)
ksi (MPa)
Ftu (A)
ksi (MPa)
7085-T7451 (AMS 4470)
% El. (S)
(4D)
Fty (A)
ksi (MPa)
Ftu (A)
ksi (MPa)
% El. (S)
(4D)
L
68 (469)
73 (503)
11
LT
66 (455)
73 (503)
8
ST
61 (421)
72 (496)
4
L
72 (496)
75 (517)
9
68 (469)
73 (503)
10
LT
69 (476)
76 (524)
7
66 (455)
73 (503)
7
ST
65 (448)
74 (510)
3
61 (421)
71 (490)
4
L
72 (496)
75 (517)
8
68 (469)
72 (496)
9
LT
69 (476)
76 (524)
7
65 (448)
73 (503)
6
ST
65 (448)
73 (503)
3
61 (421)
70 (483)
4
L
71 (490)
74 (510)
8
67 (462)
72 (496)
8
LT
67 (462)
75 (517)
5
64 (441)
72 (496)
5
ST
64 (441)
72 (496)
3
60 (414)
69 (476)
4
Fracture Toughness • 7085 Plate • Minimum Values (S-Basis)
Thickness
Inch (mm)
L-T
7085-T7651 (AMS 4329)
7085-T7451 (AMS 4470)
KIc, ksi√in (MPa√m)
KIc, ksi√in (MPa√m)
T-L
S-L
3.000-4.000 (76.20-101.60)
L-T
T-L
S-L
36 (40)
27 (30)
27 (30)
4.001-5.000 (101.62-127.00)
29 (32)
24 (26)
24 (26)
32 (35)
25 (27)
26 (29)
5.001-6.000 (127.02-152.40)
27 (30)
22 (24)
23 (25)
29 (32)
23 (25)
24 (26)
6.001-7.000 (152.42-177.80)
26 (29)
21 (23)
22 (24)
29 (32)
22 (24)
23 (25)
CORROSION RESISTANCE
The minimum guaranteed exfoliation resistance (EXCO ASTM G34) for 7085 is EB for both the T7651 and T7451 tempers.
The minimum guaranteed SCC resistance (ASTM G47) in the ST direction is 26 ksi (180 MPa) for the T7651 temper,
and 35 ksi (241 MPa) for the T7451 temper.
ALCOA AEROSPACE AND AUTOMOTIVE PRODUCTS
P.O. BOX 8025 • BETTENDORF, IOWA 52722 • 1-800-523-9596 • www.alcoa.com
Product specifications are subject to change without notice.
©2016 Alcoa Inc.
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