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7076 (7076-T61, A97076) Aluminum

7076 aluminum is a 7000-series aluminum alloy: the main alloying addition is zinc and it is formulated for primary forming into wrought products. Cited properties are appropriate for the T61 temper. To achieve this temper, the metal is solution heat-treated and artificially underaged. The degree of underaging is different from T64 and T65. 7076 is the Aluminum Association (AA) designation for this material. In European standards, it will be given as EN AW-7076. A97076 is the UNS number.

It has been in use since 1940, but has only received its standard designation in 1954.

The graph bars on the material properties cards below compare 7076 aluminum to: 7000-series alloys (top), all aluminum alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

Mechanical Properties

Brinell Hardness

160

Elastic (Young's, Tensile) Modulus

70 GPa 10 x 106 psi

Elongation at Break

6.2 %

Fatigue Strength

170 MPa 24 x 103 psi

Poisson's Ratio

0.32

Shear Modulus

27 GPa 3.9 x 106 psi

Shear Strength

310 MPa 45 x 103 psi

Tensile Strength: Ultimate (UTS)

530 MPa 77 x 103 psi

Tensile Strength: Yield (Proof)

460 MPa 67 x 103 psi

Thermal Properties

Latent Heat of Fusion

380 J/g

Maximum Temperature: Mechanical

170 °C 340 °F

Melting Completion (Liquidus)

630 °C 1170 °F

Melting Onset (Solidus)

460 °C 850 °F

Specific Heat Capacity

860 J/kg-K 0.21 BTU/lb-°F

Thermal Conductivity

140 W/m-K 81 BTU/h-ft-°F

Thermal Expansion

24 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

35 % IACS

Electrical Conductivity: Equal Weight (Specific)

100 % IACS

Otherwise Unclassified Properties

Base Metal Price

9.5 % relative

Density

3.0 g/cm3 190 lb/ft3

Embodied Carbon

8.0 kg CO2/kg material

Embodied Energy

150 MJ/kg 63 x 103 BTU/lb

Embodied Water

1110 L/kg 130 gal/lb

Common Calculations

Resilience: Ultimate (Unit Rupture Work)

31 MJ/m3

Resilience: Unit (Modulus of Resilience)

1510 kJ/m3

Stiffness to Weight: Axial

13 points

Stiffness to Weight: Bending

45 points

Strength to Weight: Axial

49 points

Strength to Weight: Bending

48 points

Thermal Diffusivity

54 mm2/s

Thermal Shock Resistance

23 points

Alloy Composition

Among wrought aluminum alloys, the composition of 7076 aluminum is notable for containing a comparatively high amount of zinc (Zn). Zinc is used to achieve significant increases in strength, at the cost of increased susceptibility to stress corrosion cracking. Among other things, this limits weldability.

Aluminum (Al) 86.9 to 91.2
Zinc (Zn) 7.0 to 8.0
Magnesium (Mg) 1.2 to 2.0
Copper (Cu) 0.3 to 1.0
Manganese (Mn) 0.3 to 0.8
Iron (Fe) 0 to 0.6
Silicon (Si) 0 to 0.4
Titanium (Ti) 0 to 0.2
Residuals 0 to 0.15

All values are % weight. Ranges represent what is permitted under applicable standards.

Followup Questions

Similar Alloys

Further Reading

ASTM B247: Standard Specification for Aluminum and Aluminum-Alloy Die Forgings, Hand Forgings, and Rolled Ring Forgings

ASM Specialty Handbook: Aluminum and Aluminum Alloys, J. R. Davis (editor), 1993

CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015