The major alloying elements in 7XXX series alloys are Zn, Mg, and Cu. Both weldable Al-Zn-Mg and non-weldable Al-Zn-Mg-Cu alloys are heat-treatable. Zn and Mg form η”-MgZn2 fine precipitates, which are the main source of strengthening. Apart from designing the most appropriate ratios of main alloying elements, we take great pains to maintain low levels of impurities Si and Fe, ensuring that alloys in this series offer high strength, high toughness, and excellent formability. Typical tensile strength: 220~610 MPa (32~88 ksi). Mainly used in aerospace, automotive, sports, and consumer electronic products.
The 7000 series of moderately strong, weldable aluminum alloys offer good weldability; they can be used in products with high cosmetic finish, high strength and fracture toughness needs. Examples include: consumer electronic products, motorcycle/bicycle frames and relevant motor vehicle components, and baseball and softball bats. To improve weather and pressure resistance.
Typical alloys: 7003, 7005, 7046, etc.
7XXX series high-strength aluminum alloys, also known as super duralumin, have poor weldability, but can be used in products required high strength and fatigue resistance, such as bicycle front forks, baseball/softball bats, aerospace structures, auto and motorcycle/bicycle parts and components and aluminum fastener and wrie.
Typical alloys: 7001, 7050, 7075, 7068, etc.