What Are the Properties of 7075 Aluminum Alloy?
7075 aluminum alloy is well known for its outstanding mechanical performance. Its key properties include:
Corrosion Behavior:
7075 aluminum alloy provides moderate corrosion resistance when compared with 5xxx and 6xxx series alloys. However, it is especially vulnerable to stress-corrosion cracking, particularly in high-stress conditions or chloride-rich environments. For this reason, protective treatments are commonly applied.
Melting Range:
The alloy has a melting range of 477–635°C (891–1175°F), which is lower than that of many steels, making forming and processing easier.
Chemical Reactivity:
Although its precipitation-hardened structure delivers high strength, 7075 aluminum alloy can still react with strong acids and alkalis. In aggressive service environments, protective coatings are recommended to maintain durability.
Density:
With a density of 2.81 g/cm³, 7075 aluminum alloy offers an excellent strength-to-weight ratio, making it ideal for lightweight structural applications.
Galvanic Corrosion:
When 7075 aluminum alloy comes into contact with dissimilar metals-especially in corrosive environments-it may experience galvanic corrosion due to differences in electrochemical potential. Proper isolation and surface protection are therefore essential.
What Are the Mechanical Properties of 7075 Aluminum Alloy?
The 7075-T6 temper is particularly favored in aerospace and other high-stress applications because of its superior mechanical characteristics:
Tensile Strength:
7075-T6 aluminum alloy has a tensile strength of approximately 572 MPa (83,000 psi), enabling it to withstand very high applied loads.
Yield Strength:
Its yield strength typically ranges from 480 to 505 MPa (69,000–73,000 psi). Lower-strength tempers, such as T651, generally exhibit yield strengths starting around 430 MPa.
Elongation at Break:
Elongation at break for 7075-T6 usually falls between 5% and 9%, reflecting its relatively low ductility compared with softer aluminum alloys.
Young's Modulus:
The Young's modulus of 7075 aluminum alloy is about 71.7 GPa (10,400 ksi), indicating high stiffness.
Hardness:
In the T6 condition, the alloy typically shows a Rockwell hardness of about 87 HRB.
Does 7075 Aluminum Alloy Retain Its Properties at High Temperatures?
No. The yield strength of 7075 aluminum alloy begins to decline significantly above approximately 120°C and may decrease by nearly 40 % at around 150°C. As a result, it is not recommended for high-stress applications at elevated temperatures. However, the alloy maintains good toughness and strength at cryogenic temperatures, making it suitable for low-temperature service.
How Is 7075 Aluminum Alloy Manufactured?
The production of 7075 aluminum alloy involves several controlled steps. Pure aluminum is melted and alloyed with elements such as zinc, magnesium, and copper. The molten metal is typically direct-chill cast into billets, followed by homogenization. Subsequent processes include hot rolling or extrusion, solution heat treatment (around 470°C), rapid quenching, and precipitation aging to achieve the desired temper, such as T6 or T73. GNEE carefully controls each stage to ensure consistent quality and performance.
How Much Does 7075 Aluminum Alloy Cost?
The price of 7075 aluminum alloy varies considerably depending on the product form, temper, specifications, and order volume. For example, 7075 aluminum powder may cost anywhere from USD 20 to USD 500 per kilogram, depending on purity and particle size. Prices for plates, sheets, bars, or tubes are typically quoted based on current market conditions and customer requirements. For accurate pricing, GNEE provides customized quotations according to specification and quantity.
