7075 T6 Aluminum

7075-T6 aluminum alloy is a high-strength, precipitation-hardened aluminum alloy, with zinc (Zn), magnesium (Mg), and copper (Cu) as the primary alloying elements. It has excellent mechanical properties and corrosion resistance. Due to its good strength-to-density ratio, fracture toughness, and resistance to stress corrosion cracking (SCC), it is widely used in the aerospace and automotive industries.

7075-T6 aluminum alloy has one of the highest strengths among all aluminum alloys. The mechanical properties of 7075-T6 are achieved through solution heat treatment and artificial aging processes, resulting in excellent strength, corrosion resistance, and a certain degree of machinability.

Due to its excellent strength and performance, 7075-T6 aluminum alloy has become one of the preferred materials in aerospace, military, and high-end industrial fields. Although its machinability, corrosion resistance, and weldability are relatively weaker, its high strength and outstanding mechanical properties make it very popular in demanding applications.

7075 T6 Aluminum Heat Treatment Process

• Solution heat treatment: First, the cast 7075 aluminum alloy is heated to around 450°C for homogenization. This process ensures that the elements in the alloy dissolve completely, forming a uniform solid solution.
• Quenching: Then, the alloy is rapidly cooled to lock in the dissolved state, which helps achieve higher strength.
• Artificial aging: After quenching, the 7075 aluminum alloy is heated to 120°C and held for 24 hours. During this time, the dissolved elements precipitate, forming strengthening phases that bring the material’s strength to its peak.

Through this treatment process, 7075 aluminum alloy achieves its highest strength, but it also comes with some drawbacks, such as relatively poor weldability.

7075 T6 Aluminum Mechanical Properties

7075-T6 aluminum alloy has very high strength, which makes it an ideal choice for high-strength applications, especially in the aerospace field.

7075 T6 Aluminum Chemical Composition

• Major alloying elements: The primary elements in 7075 aluminum alloy are zinc, magnesium, and copper. Zinc is the main strengthening element, copper provides strength and corrosion resistance, and magnesium enhances the alloy's strength and machinability.
• Precipitation hardening: 7075 aluminum alloy uses precipitation hardening to improve its mechanical properties. Through solution heat treatment, quenching, and aging processes, it reaches a high-strength state.

7075 T6 Aluminum Low Temperature Performance

7075-T6 aluminum alloy exhibits excellent performance in low-temperature environments, making it particularly suitable for applications such as cryogenic storage and fuel tanks. For example, storage containers for liquid hydrogen, liquid oxygen, and other cryogenic fuels must withstand high stress at extremely low temperatures. 7075-T6 aluminum alloy has good crack resistance at low temperatures and maintains its strength and toughness at extreme low temperatures, such as -196°C (liquid nitrogen temperature).

7075 T6 Aluminum Stress Corrosion Cracking (SCC) Resistance

7075-T6 aluminum alloy has excellent stress corrosion cracking (SCC) resistance, which makes it perform exceptionally well in aerospace and military applications, especially in humid and corrosive environments. Although its corrosion resistance is superior to many other aluminum alloys, it still requires surface treatments, such as anodizing, to enhance its protection in some extreme environments.

7075 T6 Aluminum Machinability and Surface Treatment

The machinability of 7075 aluminum alloy is medium; it is relatively hard, requiring higher cutting forces during machining. However, with appropriate tools and processes, 7075 can still achieve high machining accuracy. In addition, 7075 aluminum alloy responds well to anodizing, forming a corrosion-resistant surface coating that improves its durability in harsh environments.

7075 T6 Aluminum Corrosion Resistance

The corrosion resistance of 7075-T6 aluminum alloy is considered medium among aluminum alloys. While it can resist most corrosive environments, its corrosion resistance is not as ideal as some other alloys, such as 5083. To improve its corrosion performance, 7075 aluminum alloy is often enhanced by surface treatments like anodizing.

7075 T6 Aluminum Applications

7075 T6 Aluminum Product Forms

• Round Bars, Square Bars, Hexagonal Bars: 7075-T6 aluminum alloy is widely used in the form of round bars, square bars, and hexagonal bars for high-strength structural parts such as aerospace components and mechanical fittings. These forms of aluminum alloy play an important role in applications requiring high strength and durability, especially in components that need to withstand high loads and harsh conditions.
• Rectangular Bars, Square Tubes, Round Tubes: 7075-T6 aluminum alloy in the form of rectangular bars, square tubes, and round tubes is commonly used in aerospace structural components, rails, and other applications. These products, known for their excellent strength and rigidity, are widely used in aircraft frames, structural supports, and other high-strength mechanical structures, ensuring stability and safety in critical applications.
• Plates and Thin Sheets: 7075-T6 aluminum alloy plates and thin sheets are primarily used to manufacture aircraft fuselages, ship structures, and load-bearing components. These products offer outstanding strength and corrosion resistance and are widely used in structures that require lightweight, high strength, and the ability to withstand environmental pressures, such as aircraft exteriors and structural support parts in ships.

7075 T6 Aluminum Weldability and Drawbacks

7075-T6 aluminum alloy has poor weldability due to its high strength and high alloy content. Cracking is common during welding, so it is generally unsuitable for welding, especially in the T6 temper. To avoid welding issues, other alloys (such as 6061) are often chosen, or special welding techniques are employed when necessary.