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.
| Al | 86.9 to 91.2 | |
| Zn | 7.0 to 8.0 | |
| Mg | 1.2 to 2.0 | |
| Cu | 0.3 to 1.0 | |
| Mn | 0.3 to 0.8 | |
| Fe | 0 to 0.6 | |
| Si | 0 to 0.4 | |
| Ti | 0 to 0.2 | |
| res. | 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