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. 1/16