All About 7075 Aluminum Alloy (Properties, Strength, and Applications)

7075 aluminum is a high-performance alloy with superior mechanical properties, high tensile strength, ductility, toughness, and fatigue resistance. It has better corrosion resistance than other 2000 series alloys and is commonly used in highly stressed structural applications, particularly in aircraft. Developed in Japan in 1935, it was reverse-engineered by Alcoa in the US in 1943 for military aircraft production. This article will discuss its composition, characteristics, properties, and applications.

All About 7075 Aluminum Alloy (Properties, Strength, and Applications)

Characteristics of 7075 Aluminum

7075 aluminum is a type of aluminum alloy that has some specific characteristics. It has high strength, average corrosion resistance, and poor weldability. This alloy is made by combining high zinc and chromium contents. Zinc has dual effects in assisting with precipitation hardening and delivering higher yield stress and ultimate tensile strength. Zinc enhances strength by inhibiting partial dislocation, while high chromium content reduces crystal growth, enhancing toughness and ductility.

7075 aluminum is also known as 7075 aircraft aluminum or aviation aluminum. It is widely used for structural parts and skin elements. Structural parts are usually in the T7X series temper, whereas skin sheets are generally in the T6 temper. Fatigue resilience of 7075 aluminum is similar to 2000-series alloys, making it ideal for most aircraft and structural components of rockets.

7075 aluminum plate

7075 aluminum plate

   7075 Aluminum Composition

Al 7075 Composition According to Aluminum Association
Element% Composition
Others Each0.05
Others Total0.15

7075 Aluminum Properties-T6 

7075-T6 Aluminium Mechanical Properties
Tensile Strength: Yield (Proof)480 Mpa
Elastic (Young’s, Tensile) Modulus70 GPa
Tensile Strength: Ultimate (UTS) 560 MPa
Elongation at break7.9%.
Fatigue Strength160 Mpa
Shear Modulus  26 Gpa
Shear Strength 330 MPa.
Poisson’s Ratio0.32
Brinell Hardness150
7075 T6 Aluminium Thermal Properties
Thermal Conductivity 130 W/m-K (75 BTU/h-ft-°F)
Thermal Expansion 23 µm/m-K
Melting Point 480 °C (890 °F)
Specific Heat Capacity870 J/kg-K (0.21 BTU/lb-°F)
Aluminum Alloy 7075 T6  Electrical Properties
Electrical Conductivity: Equal Weight (Specific) 98 % IACS
Electrical Conductivity: Equal Volume33 % IACS

7075 Al Alloy Application Industry

The 7000 aluminum alloy is used in a wide range of applications. Among these, 7075 aluminum alloy is particularly popular due to its lightweight and toughness properties. It is highly valued by both product users and manufacturers alike. The aerospace, aircraft, and automotive industries extensively utilize this alloy due to its exceptional fatigue resistance, which makes it ideal for applications that involve continual movement and pressure changes.

7075 alloy aluminum  is extensively used to develop aircraft structures, such as fuselages and wings. It is also used in other fields, including recreation, for the production of bicycle components, rock climbing equipment, archery equipment, and firearms. The military has used 7075 aluminum alloy in the manufacture of M-16 rifles.

7075 aluminum alloy is available in various forms to meet the diverse needs of different applications. Aluminum bars, in particular, are widely used for high-stress applications. For producing bicycle components, military-grade rifles, or plastic industry molds, 7075 is often the alloy of choice. Highly stressed structural components, such as gears, fuse parts, and bows, are also manufactured using 7075 aluminum alloy.

7075 aluminum tube

7075 aluminum tube

Machining Operations

Grade 7075 is an Aluminum Alloy known for its excellent machinability, which is good for CNC machining. This alloy is heat treated to disperse the alloying elements uniformly around the base element of aluminum. The result is a product that is easy to machine at high speeds and does not clog up the cutting tools.

 Common Trade Names and Standards of 7075 Aluminum

The Aluminum Association (AA) has designated it as 7075, also called AE Alloys, Zicral, Aluminum v95, Fortal Constructal, and Ergal, and different standards as below:

EN: EN AW-7075/AlZn5.5MgCu EN573-3-1994

CN:7A09 GB/T3190–2008

Japan:A7075 JIS H4000-1999 JIS H4080-1999

Germany: AlZnMgCu1.5/3.4365 DIN172.1-1986/w-nr

France:7075 A-Z5GU NFA50-411 NFA50-451

USA:7075/A97075 AA/UNS

UK:7075 C77S BS 1470-1988

Advantages and Disadvantages of 7075-T6 Aluminium

7075 aluminum is the strongest alloy used in various industrial applications with easy machinability, corrosion resistance, and lightweight properties. It is suitable for aerospace applications, as it has a visually appealing finish when polished, reducing the need for painting. 

7075 aluminum consists of 90% aluminum, 5.6% zinc, 2.5% magnesium, and 1.6% copper, with a density of .102 lbs/ cubic inch. It has high fatigue strength and a high-strength-to-density ratio, making it ideal for military rifles and rock climbing. 

However, when choosing 7075-T6 aluminum alloy, it is essential to consider its limitations. It has lower corrosion resistance than other aluminum alloys, and its ductility is inferior to other 7000-series alloys. Additionally, its cost is relatively high, which can limit its use and availability.

7075 aluminum square tube

7075 aluminum square tube


Is 7075 aluminum weldable?

7075 is considered unweldable through the arc welding process, making it unsafe for structural purposes. It poses a challenge to many welders.

7075 aluminum welding

7075 aluminum welding

Which one is stronger? 7075 Aluminum or stainless steel 304?

7075 is an aluminum alloy that contains zinc. It is strong and has good fatigue resistance and average machinability.Wrought aluminum grades of 7075 have a maximum tensile strength greater than 572 MPa and a 2.8 g/cm3 density. Comparatively, 304-grade stainless steel has a density of 8 g/cm3 and a tensile strength of 621 MPa. It means that 7075 aluminum possesses 90% of the strength of 304 stainless steel while weighing only a third as much. Therefore, an equivalent weight of 7075 aluminum is nearly three times as strong as an equal mass part made from 304 stainless steel.