2618A (2618A-T851, AlCu2Mg1.5Ni) Aluminum
2618A aluminum is a 2000-series aluminum alloy: the main alloying addition is copper, and it is formulated for primary forming into wrought products. Cited properties are appropriate for the T851 temper. To achieve this temper, the metal is solution heat-treated, stress relieved, then artificially aged. The stress relief is accomplished by stretching the metal by an amount that depends on the type of standard wrought product being made (sheet, plate, bar, or forging). 2618A is the Aluminum Association (AA) designation for this material. In European standards, it will be given as EN AW-2618A. Additionally, the EN chemical designation is AlCu2Mg1,5Ni. The British Standard (BS) designation is H16. And the AFNOR (French) designation is A-U2GN.
It originally received its standard designation in 1972.
The graph bars on the material properties cards below compare 2618A aluminum to: 2000-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
72 GPa 10 x 106 psi
Elongation at Break
4.5 %
Fatigue Strength
120 MPa 18 x 103 psi
Poisson's Ratio
0.33
Shear Modulus
27 GPa 3.9 x 106 psi
Shear Strength
260 MPa 37 x 103 psi
Tensile Strength: Ultimate (UTS)
440 MPa 64 x 103 psi
Tensile Strength: Yield (Proof)
410 MPa 60 x 103 psi
Thermal Properties
Latent Heat of Fusion
390 J/g
Maximum Temperature: Mechanical
230 °C 450 °F
Melting Completion (Liquidus)
670 °C 1240 °F
Melting Onset (Solidus)
560 °C 1040 °F
Specific Heat Capacity
880 J/kg-K 0.21 BTU/lb-°F
Thermal Conductivity
150 W/m-K 89 BTU/h-ft-°F
Thermal Expansion
23 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
37 % IACS
Electrical Conductivity: Equal Weight (Specific)
110 % IACS
Otherwise Unclassified Properties
Base Metal Price
11 % relative
Density
3.0 g/cm3 180 lb/ft3
Embodied Carbon
8.4 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)
19 MJ/m3
Resilience: Unit (Modulus of Resilience)
1180 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
47 points
Strength to Weight: Axial
41 points
Strength to Weight: Bending
44 points
Thermal Diffusivity
59 mm2/s
Thermal Shock Resistance
19 points
Alloy Composition
Among wrought aluminum alloys, the composition of 2618A aluminum is notable for containing a comparatively high amount of iron (Fe) and including nickel (Ni). Most of the time, iron is an impurity in aluminum alloys. However, it may be added in quantity to improve strength (particularly at high temperatures) without much impact on electrical properties. Nickel is used to increase mechanical strength at elevated temperatures, and to reduce thermal expansion. However, it can increase susceptibility to pitting corrosion in certain alloys.
| Al | 91.5 to 95.2 | |
| Cu | 1.8 to 2.7 | |
| Mg | 1.2 to 1.8 | |
| Fe | 0.9 to 1.4 | |
| Ni | 0.8 to 1.4 | |
| Si | 0.15 to 0.25 | |
| Mn | 0 to 0.25 | |
| Zr | 0 to 0.25 | |
| Ti | 0 to 0.2 | |
| Zn | 0 to 0.15 | |
| res. | 0 to 0.15 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
Iron in Aluminium Alloys: Impurity and Alloying Element, N. A. Belov et al., 2002
EN 485-2: Aluminium and aluminium alloys. Sheet, strip and plate. Mechanical properties
EN 573-3: Aluminium and aluminium alloys. Chemical composition and form of wrought products. Chemical composition and form of products
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015