What is 7049 aluminum made of?

7049 aluminum alloy is a high-strength aluminum alloy mainly composed of aluminum, zinc, copper, and magnesium, offering excellent strength. However, due to the addition of zinc and copper, its corrosion resistance and weldability are relatively poor.

7049 aluminum alloy is a high-strength aluminum alloy primarily composed of aluminum (Al), zinc (Zn), copper (Cu), and magnesium (Mg), among other elements. The composition is designed to enhance strength to meet the demands of high-performance applications, but this comes with some trade-offs, particularly in terms of weldability and corrosion resistance.

7049 Aluminum Alloy Composition Information

• Aluminum (Al): 85.7% to 89.5%. Aluminum is the primary component of 7049 alloy, providing light weight and good formability.
• Zinc (Zn): 7.2% to 8.2%. Zinc is one of the most significant alloying elements in 7049 aluminum, significantly improving the strength of the alloy. However, the addition of zinc also increases the sensitivity of the alloy to stress corrosion cracking, limiting its use in environments where high weldability and corrosion resistance are required.
• Magnesium (Mg): 2.0% to 2.9%. The addition of magnesium enhances the strength of the alloy and improves its mechanical properties. Magnesium also contributes to better corrosion resistance but has a minimal effect on weldability.
• Copper (Cu): 1.2% to 1.9%. Copper further enhances the strength of the alloy but also decreases its corrosion resistance and weldability. Copper is especially important in applications requiring high strength.
• Iron (Fe): Maximum 0.35%. The iron content is generally low. While iron may affect the mechanical properties of the aluminum alloy, its impact on 7049 aluminum is minimal.
• Chromium (Cr): Maximum 0.22%. Chromium helps to improve the corrosion resistance of the alloy and provides a certain level of hardness.
• Silicon (Si): Maximum 0.25%. Silicon is present in low amounts and primarily affects the castability of the alloy, improving its oxidation resistance.
• Manganese (Mn): Maximum 0.2%. Manganese helps to enhance the strength and corrosion resistance of the alloy, especially with regard to its heat resistance.
• Titanium (Ti): Maximum 0.1%. Titanium helps to refine the grain structure, improving the alloy's mechanical properties and corrosion resistance.
• Residual elements: Maximum 0.15%. These elements may come from raw materials or impurities in the production process. Their presence typically does not significantly affect the performance of the alloy but may have a slight impact on certain properties.

7049 Aluminum Alloy Composition

7049 Aluminum Alloy Characteristics

High Strength: Due to the high content of zinc and copper, 7049 aluminum alloy has very high strength, making it suitable for applications that endure high loads.

Poor Weldability: The addition of zinc and copper reduces the weldability of the alloy, limiting its use in applications that require welding.

Lower Corrosion Resistance: Although elements like magnesium and chromium help with corrosion resistance, the presence of zinc and copper makes 7049 aluminum alloy more susceptible to stress corrosion cracking, particularly in certain corrosive environments.

7049 aluminum alloy enhances its strength with a high content of zinc and copper, making it suitable for high-strength structural components and parts. However, these elements also result in trade-offs in corrosion resistance and weldability. As a result, it is typically used in aerospace and other fields where high strength is a critical requirement, but it is not suitable for welding or long-term exposure to corrosive environments.