6081 (6081-T6, AlSi0.9MgMn) Aluminum
6081 aluminum is a 6000-series aluminum alloy: there is significant alloying with both magnesium and silicon, and the alloy is formulated for primary forming into wrought products. Cited properties are appropriate for the T6 temper. To achieve this temper, the metal is solution heat-treated and artificially aged until it meets standard mechanical property requirements. 6081 is the Aluminum Association (AA) designation for this material. In European standards, it will be given as EN AW-6081. Additionally, the EN chemical designation is AlSi0,9MgMn. And the UNS number is A96081.
It originally received its standard designation in 1972.
The graph bars on the material properties cards below compare 6081 aluminum to: 6000-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
9.0 %
Fatigue Strength
110 MPa 15 x 103 psi
Poisson's Ratio
0.33
Shear Modulus
26 GPa 3.8 x 106 psi
Shear Strength
180 MPa 26 x 103 psi
Tensile Strength: Ultimate (UTS)
310 MPa 45 x 103 psi
Tensile Strength: Yield (Proof)
270 MPa 40 x 103 psi
Thermal Properties
Latent Heat of Fusion
410 J/g
Maximum Temperature: Mechanical
160 °C 320 °F
Melting Completion (Liquidus)
640 °C 1190 °F
Melting Onset (Solidus)
610 °C 1130 °F
Specific Heat Capacity
900 J/kg-K 0.22 BTU/lb-°F
Thermal Conductivity
180 W/m-K 100 BTU/h-ft-°F
Thermal Expansion
23 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
47 % IACS
Electrical Conductivity: Equal Weight (Specific)
160 % IACS
Otherwise Unclassified Properties
Base Metal Price
9.5 % relative
Density
2.7 g/cm3 170 lb/ft3
Embodied Carbon
8.3 kg CO2/kg material
Embodied Energy
150 MJ/kg 66 x 103 BTU/lb
Embodied Water
1180 L/kg 140 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
27 MJ/m3
Resilience: Unit (Modulus of Resilience)
540 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
50 points
Strength to Weight: Axial
32 points
Strength to Weight: Bending
37 points
Thermal Diffusivity
74 mm2/s
Thermal Shock Resistance
14 points
Alloy Composition
Among wrought aluminum alloys, the composition of 6081 aluminum is notable for containing comparatively high amounts of silicon (Si) and magnesium (Mg). Silicon is used to increase strength at the expense of ductility. It also lowers the melting temperature and raises the fluidity of the alloy. Magnesium promotes hardenability through both heat treatment and strain hardening mechanisms. It also increases susceptibility to intergranular corrosion.
| Al | 96.3 to 98.6 | |
| Si | 0.7 to 1.1 | |
| Mg | 0.6 to 1.0 | |
| Mn | 0.1 to 0.45 | |
| Fe | 0 to 0.5 | |
| Zn | 0 to 0.2 | |
| Ti | 0 to 0.15 | |
| Cr | 0 to 0.1 | |
| Cu | 0 to 0.1 | |
| res. | 0 to 0.15 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
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
Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM Handbook vol. 2, ASM International, 1993