MakeItFrom.com
Menu (ESC)

7108A (AlZn5Mg1Zr) Aluminum

7108A aluminum is a 7000-series aluminum alloy: the main alloying addition is zinc and it is formulated for primary forming into wrought products. 7108A is the Aluminum Association (AA) designation for this material. In European standards, it will be given as EN AW-7108A.

It originally received its standard designation in 1987.

The properties of 7108A aluminum include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare 7108A 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

Elastic (Young's, Tensile) Modulus

69 GPa 10 x 106 psi

Elongation at Break

11 to 13 %

Fatigue Strength

120 to 130 MPa 18 to 19 x 103 psi

Poisson's Ratio

0.33

Shear Modulus

26 GPa 3.8 x 106 psi

Shear Strength

210 MPa 30 to 31 x 103 psi

Tensile Strength: Ultimate (UTS)

350 MPa 50 to 51 x 103 psi

Tensile Strength: Yield (Proof)

290 to 300 MPa 42 to 43 x 103 psi

Thermal Properties

Latent Heat of Fusion

380 J/g

Maximum Temperature: Mechanical

210 °C 410 °F

Melting Completion (Liquidus)

630 °C 1170 °F

Melting Onset (Solidus)

520 °C 970 °F

Specific Heat Capacity

870 J/kg-K 0.21 BTU/lb-°F

Thermal Conductivity

150 W/m-K 86 BTU/h-ft-°F

Thermal Expansion

24 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

36 % IACS

Electrical Conductivity: Equal Weight (Specific)

110 % IACS

Otherwise Unclassified Properties

Base Metal Price

10 % relative

Density

2.9 g/cm3 180 lb/ft3

Embodied Carbon

8.3 kg CO2/kg material

Embodied Energy

150 MJ/kg 66 x 103 BTU/lb

Embodied Water

1150 L/kg 140 gal/lb

Common Calculations

Resilience: Ultimate (Unit Rupture Work)

38 to 44 MJ/m3

Resilience: Unit (Modulus of Resilience)

610 to 640 kJ/m3

Stiffness to Weight: Axial

13 points

Stiffness to Weight: Bending

47 points

Strength to Weight: Axial

33 to 34 points

Strength to Weight: Bending

38 points

Thermal Diffusivity

59 mm2/s

Thermal Shock Resistance

15 to 16 points

Alloy Composition

Among wrought aluminum alloys, the composition of 7108A aluminum is notable for including gallium (Ga) and containing a comparatively high amount of zinc (Zn). Gallium is used to improve corrosion resistance and to modify an alloy's response to etching, brightening, and similar treatments. 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) 91.6 to 94.4
Zinc (Zn) 4.8 to 5.8
Magnesium (Mg) 0.7 to 1.5
Zirconium (Zr) 0.15 to 0.25
Iron (Fe) 0 to 0.3
Silicon (Si) 0 to 0.2
Manganese (Mn) 0 to 0.050
Copper (Cu) 0 to 0.050
Chromium (Cr) 0 to 0.040
Titanium (Ti) 0 to 0.030
Gallium (Ga) 0 to 0.030
Residuals 0 to 0.15

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

Followup Questions

Similar Alloys

Further Reading

Handbook of Aluminum vol. 2: Alloy Production and Materials Manufacturing, George Totten and D. Scott MacKenzie (editors), 2003

Aluminum: Properties and Physical Metallurgy, John E. Hatch (editor), 1984

EN 755-2: Aluminium and aluminium alloys. Extruded rod/bar, tube and profiles. Mechanical properties

EN 573-3: Aluminium and aluminium alloys. Chemical composition and form of wrought products. Chemical composition and form of products