Aluminum 6063 properties
Chemical composition
Section titled “Chemical composition”The nominal chemical composition of aluminum 6063 according to EN 573-3 and AA standards is detailed in the following table (percentages by mass). Aluminum (Al) constitutes the remainder.
| Element | Minimum (%) | Maximum (%) |
|---|---|---|
| Silicon (Si) | 0,20 | 0,60 |
| Iron (Fe) | 0,00 | 0,35 |
| Copper (Cu) | 0,00 | 0,10 |
| Manganese (Mn) | 0,00 | 0,10 |
| Magnesium (Mg) | 0,45 | 0,90 |
| Zinc (Zn) | 0,00 | 0,10 |
| Titanium (Ti) | 0,00 | 0,10 |
| Chromium (Cr) | 0,00 | 0,10 |
| Others | 0,00 (each) | 0,05 (each), total 0,15 |
| Aluminum (Al) | 97,5 | 99,35 |
The 6063A variant has an adjustment in the limits of Si (0,30‑0,60 %), Fe (0,15‑0,35 %), Mn (0,00‑0,15 %), and Cr (0,00‑0,05 %), keeping the other elements the same.
Mechanical properties
Section titled “Mechanical properties”The mechanical properties of aluminum 6063 depend on the temper (heat treatment state) and product geometry. The following tables list representative minimum values for extrusions according to BS EN 755-2, unless otherwise indicated.
| Property | Temper O | Temper T4 | Temper T5 | Temper T6 |
|---|---|---|---|---|
| Tensile strength, Rm | ≤130 MPa (≤18,9 ksi) | 150 MPa (21,8 ksi) | 160 MPa (23,2 ksi) | 215 MPa (31,2 ksi) |
| Yield strength, Rp0,2 | Not specified | 90 MPa (13,1 ksi) | 110 MPa (16,0 ksi) | 170 MPa (24,7 ksi) |
| Elongation A50 (50 mm gauge length) | 16 % minimum | 10 % minimum | 6 % minimum | 8 % minimum |
| Elongation A | 18 % minimum | 12 % minimum | — | 10 % minimum |
| Brinell hardness (HBW) | 25 HB | 50 HB | 65 HB | 75 HB |
For larger thickness sections or different products (bars, tubes, profiles) values may vary slightly:
- Bars 150 to 200 mm in T6: Rm ≥195 MPa, Rp0,2 ≥160 MPa.
- Tubes in T6 with thickness ≤25 mm: Rp0,2 ≥170 MPa, Rm ≥215 MPa.
- Profiles in T6 with thickness ≤10 mm: Rm ≥215 MPa, Rp0,2 ≥170 MPa.
- The 6063A variant in T6 reaches Rm ≥230 MPa and Rp0,2 ≥190 MPa.
Physical properties
Section titled “Physical properties”| Property | Value (SI) | Value (Imperial) |
|---|---|---|
| Density | 2,69 g/cm³ | 0,097 lb/in³ |
| Modulus of elasticity (Young) | 68,9 GPa | 10 000 ksi |
| Shear modulus (rigidity) | 26,0 GPa | 3 770 ksi |
| Poisson’s ratio | 0,33 | 0,33 |
Thermal properties
Section titled “Thermal properties”| Property | Value (SI) | Value (Imperial) |
|---|---|---|
| Melting temperature (range) | 615 °C | 1 139 °F |
| Thermal conductivity | 201‑218 W/(m·K) | 116‑126 BTU/(h·ft·°F) |
| Linear thermal expansion coefficient (20‑100 °C) | 2,34 × 10⁻⁵ /K | 13,0 × 10⁻⁶ /°F |
| Specific heat | 900 J/(kg·K) | 0,215 BTU/(lb·°F) |
Electrical properties
Section titled “Electrical properties”| Property | Value (SI) | Value (Imperial) |
|---|---|---|
| Electrical resistivity (volumetric) | 30‑35 nΩ·m | 1,18‑1,38 μΩ·in (equivalent to 3,0‑3,5 μΩ·cm) |
Welding
Section titled “Welding”Aluminum 6063 is highly weldable by TIG (GTAW) and MIG (GMAW) processes. The use of filler metals 4043 (AlSi5) is recommended to minimize cracking and maintain a good surface appearance, or 5356 (AlMg5) when higher strength is required without post-treatment. The heat-affected zone reaches approximately the properties of temper O, which means a strength loss of up to 30 %. To restore the original mechanical properties, a new heat treatment of solution heat treatment and artificial aging can be applied to the entire welded part.
Fabrication
Section titled “Fabrication”Alloy 6063 is distinguished by its excellent extrudability, allowing complex shapes with thin walls and a very smooth surface finish. It anodizes easily, achieving homogeneous and decorative layers. Its cold formability is good in temper T4; in temper T6 it requires generous bend radii. Machinability is moderate, recommending carbide tools, abundant lubrication, and controlled cutting speeds. Casting processing is not recommended.
Applications by industry
Section titled “Applications by industry”- Architecture and construction: window profiles, doors, facades, curtain walls, railings, ceilings.
- Transportation: hydroformed tubes for frames, body components, trailers.
- Irrigation and conduits: agricultural and garden irrigation pipes, non-aggressive fluid ducts.
- Furniture and commercial equipment: shelves, counters, office furniture, booth structures.
- Lighting and electrical: heat sinks, LED luminaire housings, electrical conduits.
Comparison with similar materials
Section titled “Comparison with similar materials”Aluminum 6063 is used when good surface finish, high corrosion resistance, and excellent extrudability are required. Below it is compared with alloys of the same series in temper T6.
| Property | 6063‑T6 | 6061‑T6 | 6082‑T6 |
|---|---|---|---|
| Tensile strength (MPa) | 215 | 310 | 340 |
| Yield strength (MPa) | 170 | 276 | 310 |
| Typical elongation (%) | 10 | 12 | 11 |
| Surface finish | Excellent | Good | Good |
| Extrudability | Very high | Medium | Medium‑high |
| Corrosion resistance | Very good | Good | Very good |
6063 is the standard choice for visible architectural profiles, while 6061 and 6082 are preferred in structural applications demanding higher mechanical strength.
Frequently Asked Questions (FAQ)
Section titled “Frequently Asked Questions (FAQ)”What is the tensile strength of aluminum 6063 T6?
Section titled “What is the tensile strength of aluminum 6063 T6?”Aluminum 6063 in temper T6 presents a minimum tensile strength of 215 MPa (31.2 ksi) in extruded bars and profiles up to 150 mm diameter or equivalent thickness.
What Brinell hardness does 6063 reach after artificial aging?
Section titled “What Brinell hardness does 6063 reach after artificial aging?”In T6 condition, the Brinell hardness is 75 HB minimum, and in temper T5 it is around 65 HB.
At what temperature does alloy 6063 melt?
Section titled “At what temperature does alloy 6063 melt?”The melting temperature is approximately 615 °C (1 139 °F), lower than that of alloys such as 6061.
How much does it dimensionally vary with temperature?
Section titled “How much does it dimensionally vary with temperature?”The linear thermal expansion coefficient is 2.34 × 10⁻⁵ /K (13.0 × 10⁻⁶ /°F), which corresponds to an elongation of 2.34 mm per meter for each 100 °C increase.
Is it possible to weld aluminum 6063 without losing its mechanical properties?
Section titled “Is it possible to weld aluminum 6063 without losing its mechanical properties?”Yes, but welding locally reduces the strength by up to 30 % (state equivalent to temper O). Post-weld heat treatment (T6) allows recovery of almost all original properties.
What is the main difference between temper T5 and T6 in 6063?
Section titled “What is the main difference between temper T5 and T6 in 6063?”T5 is obtained by cooling after extrusion and artificial aging, offering a minimum tensile strength of 160 MPa (23.2 ksi) and a yield strength of 110 MPa (16.0 ksi). T6 involves prior solution heat treatment and artificial aging, reaching 215 MPa (31.2 ksi) tensile and 170 MPa (24.7 ksi) yield strength, with a significant increase in hardness.
References
Section titled “References”- azom.com: https://www.azom.com/article.aspx?ArticleID=2812
- engineeringtoolbox.com: https://www.engineeringtoolbox.com/properties-aluminum-pipe-d_1340.html
- steelnumber.com: https://www.steelnumber.com/en/steel_alloy_composition_eu.php?name_id=1152