What Is 7075-T6 Aluminum?
7075 aluminum alloy, supplied by GNEE, is a zinc-dominated aluminum alloy commonly known as aircraft aluminum or aerospace aluminum. It was the first high-strength Al–Zn–Mg–Cu alloy to successfully incorporate chromium, significantly improving resistance to stress-corrosion cracking in sheet products. The alloy typically contains 87.1–91.4% aluminum, with zinc at 5–6%, magnesium at 2.1–2.9%, and copper at 1.2–2.0%, along with small controlled amounts (≤0.5%) of silicon, titanium, chromium, iron, manganese, and other elements.
7075-T6 aluminum refers to the 7075 alloy in the T6 temper, achieved through solution heat treatment, homogenization of the cast alloy at approximately 450°C, rapid quenching, and subsequent artificial aging at around 120°C for 24 hours. This controlled heat-treatment process allows the alloy to reach its peak strength and standard mechanical performance.
What Makes 7075 Aluminum Stand Out?
Among all aluminum alloys, the 7075 series delivers the highest strength, reaching levels comparable to many steels. While strength is its most notable attribute, it is the combination of low density, excellent machinability, and good corrosion resistance that makes 7075 especially suitable for highly stressed structural components.
Although its corrosion resistance is lower than that of some aluminum alloys, it still performs significantly better than most 2000-series alloys. In applications where aluminum alloy 2024 is considered, 7075 is often selected instead when higher mechanical strength is required.
Basic Properties of 7075 Aluminum
Density: ~3.0 g/cm³ (190 lb/ft³)
Machinability: Excellent
Formability: Can be formed in the annealed condition and then heat treated
Springback: Higher than most aluminum alloys due to high strength
Forming Recommendation: Heating to 95–120 °C (200–250 °F) can improve formability during shaping operations
7075-T6 Mechanical Properties
Brinell Hardness: 150
Elastic (Young's) Modulus: 70 GPa
Ultimate Tensile Strength (UTS): 560 MPa
Yield Strength: 480 MPa
Elongation at Break: 7.9%
Fatigue Strength: 160 MPa
Poisson's Ratio: 0.32
Shear Modulus: 26 GPa
Shear Strength: 330 MPa
7075-T6 Thermal Properties
Solidus (Melting Onset): 480 °C (890 °F)
Specific Heat Capacity: 870 J/kg·K (0.21 BTU/lb·°F)
Thermal Conductivity: 130 W/m·K (75 BTU/h·ft·°F)
Thermal Expansion Coefficient: 23 µm/m·K
7075-T6 Electrical Properties
Electrical Conductivity (Equal Volume): 33% IACS
Electrical Conductivity (Equal Weight): 98% IACS
Applications and Uses of 7075-T6 Aluminum
Thanks to its outstanding strength-to-weight ratio, 7075-T6 aluminum supplied by GNEE is widely used across many industries, with particular emphasis on aerospace, marine, and transportation sectors. Common applications include:
Aircraft structures and fittings
Aerospace and defense components
Missiles and military equipment
Bicycle high-performance components
Tooling and precision parts
Gliders and aviation hardware
Meter gears, fuse parts, worm gears, keys, and valve components
In military applications, 7075-T6 is extensively used for assault rifle receivers, extension tubes, and precision firearms, including platforms such as the M-16.
Disadvantages of 7075-T6 Aluminum
While 7075-T6 offers an excellent balance of properties, several limitations should be considered:
Lower corrosion resistance compared with some aluminum alloys; for improved stress-corrosion resistance, 7075-T7351 may be preferred
Lowest ductility among 7000-series alloys, despite good machinability
Relatively high cost, which can limit its use in cost-sensitive applications
Conclusion
7075-T6 aluminum, supplied by GNEE, is a leading material choice for aerospace, marine, and transportation industries where lightweight design and high stress resistance are essential. Its balanced combination of extreme strength, machinability, and reliability has also made it popular across many other industrial and commercial applications.
