7075 Aluminum
7075 Aluminum is alloyed with zinc, which makes it a strong, corrosion resistant metal used in the commercial aircraft, aerospace, defense equipment and sports equipment industries. It exhibits good fatigue strength but has low workability, and is only welded by the resistance process, if at all. Because it is considered tougher than other aluminum alloys, 7075 aluminum is ideal for highly stressed parts. It is most commonly used in aircraft manufacturing to make wings and fuselages. Sports equipment such as bicycles, lacrosse sticks and rock climbing gear are made with this aluminum alloy. It has 36% the electrical conductivity of copper.
This type of aluminum alloy is developed by a heat treating process called forging at 700 degrees F. It is machined in the annealed condition at 900 degrees F for 2 hours using oil lubricants and then quenched in cold water. Finally, an aging process called precipitation strengthening is done for 24 hours, where it is heated to 250 degrees F and then cooled. 7075 aluminum is usually formed into sheets, which have good cracking resistance, structural plates up to 4 inches thick, and rods and bars. Gears, shafts, fuse parts, missile parts, valve parts and keys are all other smaller parts that are manufactured from this type of aluminum alloy. Finished parts are lightweight, semi-smooth and have a dull mill finish.