7025

7025 is a designation used for a heat-treatable aluminum alloy in the 7xxx series. It is primarily alloyed with zinc, with magnesium and copper as significant contributors to strength. The exact composition can vary by heat treatment and specification, but zinc is the principal alloying element, which gives a high strength-to-weight ratio typical of 7xxx-series alloys.

Some variants of 7025 include additions such as chromium or zirconium to improve grain structure and, in some cases, corrosion resistance. The alloy is generally supplied in wrought forms and can be shaped by rolling, extrusion, or forging.

In terms of properties, 7025 offers high ultimate tensile strength and good stiffness, with strength often increased through heat treatment to achieve a temper such as T6 or related results. It is less corrosion-resistant than many other alloys, particularly in marine environments, and atmospheric corrosion protection or coatings may be required for prolonged exposure.

Processing and welding: While machinability is reasonable, 7025 is typically not weldable with conventional fusion welding methods; if welding is required, alternative design approaches or non-heat-treatable filler alloys are often used, and joints may experience strength changes in the weld zones.

Applications and availability: 7025 is used in aerospace and other high-strength structural components where weight savings are important, such as critical fittings and brackets. Availability can vary by supplier and region, and in many applications more common alloys like 7075 are preferred for ease of production and established supply chains.

See also: aluminum alloy families, 7xxx series.