7075T651

7075T651 is a high-strength aluminum alloy designation within the 7000 series, which are primarily composed of aluminum, zinc, and magnesium. This specific temper designation indicates a heat-treated and artificially aged condition, providing enhanced mechanical properties compared to other tempers of the same alloy. The "T651" temper is achieved through solution heat treatment, followed by artificial aging and stress relief, which reduces residual stresses while maintaining high strength.

The 7075T651 alloy is widely recognized for its exceptional strength-to-weight ratio, making it suitable for aerospace, defense, and high-performance applications. It typically contains approximately 5.6% zinc, 2.3% magnesium, 1.6% copper, along with smaller amounts of chromium and other elements. The addition of these alloying elements significantly increases its tensile strength, yield strength, and hardness compared to other aluminum alloys.

This alloy is commonly used in aircraft structures, including fuselage frames, wing components, and landing gear parts, due to its ability to withstand high stresses while remaining lightweight. It is also utilized in military hardware, such as armored vehicles and precision machinery, where durability and resistance to fatigue are critical. However, its higher cost and susceptibility to corrosion and stress corrosion cracking require careful handling and protective treatments, such as anodizing or coating, in practical applications.

The mechanical properties of 7075T651 typically include a tensile strength of around 740 MPa (107,000 psi), a yield strength of approximately 655 MPa (95,000 psi), and an elongation of about 11%. These properties make it one of the strongest aluminum alloys available, though its use is often balanced against its lower ductility and formability compared to softer alloys. Proper heat treatment and fabrication techniques are essential to achieve optimal performance in structural applications.