7010 T6 Aluminum

7010 T6 aluminum alloy is one of the representative materials of high-strength wrought aluminum alloys, belonging to the Al-Zn-Mg-Cu series of ultra-high strength aluminum alloys.

7010 combines medium strength, corrosion resistance, and damage tolerance characteristics, but its corrosion resistance is still inferior to some other aluminum alloys and needs to be enhanced through cladding or surface treatments.

7010-T6 aluminum refers to 7010 aluminum in the T6 temper. To reach this temper, the metal undergoes solution heat treatment and artificial aging until it meets the required standard mechanical properties.

7010-T6 aluminum alloy is a medium-strength forged Al-Zn-Mg-Cu alloy that features high strength, excellent damage tolerance, and good resistance to stress corrosion cracking. In the T6 condition, the alloy is solution heat treated and then artificially aged to reach peak strength. Its typical ultimate tensile strength is approximately 590 MPa, and its yield strength is around 530 MPa. This alloy is mainly used to manufacture high-strength aerospace forgings and components where fatigue and corrosion resistance are critical.

7010-T6 aluminum is a high-strength 7000 series aluminum alloy, mainly used in aerospace and structural engineering. The 7010 alloy is known for its balance of strength, fatigue resistance, and resistance to stress corrosion cracking (SCC), though it is not recommended for high-temperature applications.

7010 T6 Aluminum Characteristics

‌Low-temperature performance‌: Maintains high strength below 150°C, with outstanding low-temperature strength
‌Workability‌: Good plasticity after solution treatment, but average weldability, with a tendency for stress corrosion cracking

7010 T6 Aluminum Chemical Composition

The nominal composition (weight percentage) range of 7010 aluminum alloy is as follows:

Aluminum (Al): 87.8 – 90.6%
Zinc (Zn): 5.70 – 6.70%
Magnesium (Mg): 2.10 – 2.60%
Copper (Cu): 1.50 – 2.00%
Zirconium (Zr): 0.10 – 0.16%
Trace elements (Fe, Si, Mn, Ti, Cr, Ni, and others): each element ≤ 0.15%

Precise control of zinc, magnesium, and copper content is crucial for the formation of strengthening precipitates (mainly η′ MgZn₂) during the aging process.

7010 T6 Aluminum Physical Properties

Density: 2.81 g/cm³
Melting range: start temperature 480°C, end temperature 630°C
Elastic modulus: ≈ 71 GPa
Thermal conductivity: ≈ 150 W/m·K

These values reflect the T6 condition and may vary slightly depending on specific processing techniques and tempering conditions.

7010 T6 Aluminum Mechanical Properties

In the T6 condition, 7010 aluminum exhibits the following properties:

Ultimate tensile strength (UTS): ≈ 590 MPa
Yield strength (0.2% offset): ≈ 530 MPa
Elongation at break: ≈ 4.0%
Brinell hardness: ≈ 190 HB
Fatigue strength: ≈ 180 MPa (10⁷ cycles)

These high strength and fatigue values make 7010-T6 an ideal choice for safety-critical aerospace applications.

7010 T6 Aluminum Heat Treatment

The T6 tempering process for 7xxx series alloys includes:

Solution Heat Treatment: Heating at approximately 475–480 °C for about 1 hour to dissolve soluble phases, followed by rapid quenching to retain solutes in a supersaturated solid solution.
Artificial Aging: Heating at approximately 120–200 °C for several hours (typically 3–24 hours) to induce precipitation hardening, forming fine η′ precipitates to maximize strength.
Overaging Option: To enhance stress corrosion resistance, slight overaging (e.g., T73 temper) may be used to coarsen precipitates and improve durability, at the expense of peak strength.

7010 T6 Aluminum Applications

Closed-die Forgings and Rods: Critical aerospace components such as wing spars, fuselage fittings, and landing gear parts.
High-Strength Structural Parts: Heavy-duty connectors, bulkheads, and components where damage tolerance and fatigue life are critical.
Aerospace: High-stress load-bearing parts like wing trusses, fuselage structural components, and landing gears.
Industrial Manufacturing: Structural frames in transportation vehicles, large heat exchangers, and precision molds (e.g., injection molds).
Special Uses: High-strength components in military equipment and sports gear (such as tennis rackets and softball bats).

7010-T6 is widely used in the aerospace and defense sectors due to its high strength-to-weight ratio:

Aircraft structural components (e.g., wing skins, fuselage parts)
High-stress forgings and large forged rods
Military and commercial aerospace frameworks

7010 T6 Aluminum Characteristics

High Specific Strength: Excellent strength-to-weight ratio, suitable for lightweight structural design.
High Fatigue Performance: Can endure repeated loads without crack formation.
Stress Corrosion Resistance: Good resistance to crack propagation in corrosive environments.
Moderate Weldability: Limited by high zinc content; typically joined using riveting or friction stir welding, with necessary precautions.

7010 T6 Aluminum Advantages

High Strength: Tensile and shear strengths exceed many 7000 series alloys, including 7050.
Fatigue Resistance: Suitable for cyclic load environments.
Stress Corrosion Resistance: Performs better in corrosive environments compared to traditional alloys like 7075.

7010 T6 Aluminum Limitations

Temperature Sensitivity: Strength decreases above 200 °C, not suitable for high-temperature applications.
Ductility: Lower elongation in T6 temper (4%) compared to certain 7050 tempers (up to 12%).

7010 T6 Aluminum Heat Treatment and Processing

The T6 temper enhances strength through controlled aging, but may be modified (e.g., secondary aging) to improve environmental crack resistance without significant strength loss.

Common standards include AMS 4203–4205 and EN 485-2.

Precautions

Stress Corrosion: Dual-stage aging is recommended to improve stress corrosion resistance.
Processing Limitations: Post-welding solution treatment should be avoided; non-welding forming processes are preferred.
Supply Forms: Mainly hot-rolled plates, available in thicknesses ranging from 6–300 mm and widths up to 2600 mm.

7010-T6 aluminum alloy remains the preferred material for critical aerospace forgings, offering a balanced combination of strength, fatigue resistance, and corrosion resistance.