AA7075, commonly known as 7075 aluminum alloy, is a high-strength aluminum alloy recognized for its excellent strength-to-weight ratio, making it a popular choice in demanding applications. Its exceptional properties stem from a precise blend of alloying elements.
The primary alloying elements that give 7075 aluminum its distinctive characteristics are zinc, magnesium, and copper. These elements, along with trace amounts of others, contribute to its impressive mechanical properties.
Key Alloying Elements in 7075 Aluminum
The composition of 7075 aluminum alloy is precisely controlled to achieve its high strength and other desirable attributes. The main constituents are as follows:
| Element | Approximate Percentage Range |
|---|---|
| Zinc | 5.6% – 6.1% |
| Magnesium | 2.1% – 2.5% |
| Copper | 1.2% – 1.6% |
Minor and Trace Elements
In addition to the primary elements, 7075 aluminum contains small amounts of other metals, typically less than 0.5% each, which play roles in refining its properties, such as grain structure or corrosion resistance. These include:
- Silicon
- Iron
- Manganese
- Titanium
- Chromium
- Other metals (in very minor quantities)
Understanding 7075 Tempers
The specific properties of 7075 aluminum can vary significantly depending on its "temper," which refers to the heat treatment and mechanical processing it undergoes. Common tempers for 7075 include:
- 7075-0: Annealed condition, offering the lowest strength but maximum ductility.
- 7075-T6: Solution heat-treated and artificially aged to achieve high strength and hardness. This is one of the most common and widely used tempers due to its balanced properties.
- 7075-T651: Similar to T6, but with an additional stress-relieving stretching step after heat treatment, which further improves dimensional stability and reduces internal stresses.
These precise elemental compositions and controlled heat treatments are what allow 7075 aluminum to deliver exceptional performance in applications requiring robust and lightweight materials, such as in aerospace, automotive, and sporting goods industries.
