What You Need To Know About 7075 Aluminum
Posted by Phineas Gray , on Jan, 2015
7075 Aluminum is a very high strength mix material of copper and zinc, “aircraft grade” aluminum alloy used for highly stressed structural parts. This type of aluminum has a strength level which is equal to or more than mild steels. Further, it has excellent finishing characteristics and better machinability. It can be hardened by heat treatment and/or cold working.
Applications – 7075 Aluminum is commonly used in the manufacture of aircraft and other aerospace products such as aircraft fittings, gears, shafts, keys and others.
Machinability – 7075 Aluminum is best machined when in its annealed condition. When forming 7075, oil and lubricants should be used to result in good machining.
Welding – This type of aluminum is very poor when used in welding. However, resistance welding can be done when joining is needed. Gas welding and Arc welding is not recommended, it may result in degradation of corrosion resistance.
Forming – This is an aluminum alloy which is comparatively strong, which produces greater spring back during forming. Forming can be best done when in an annealed condition. But, if difficulty arises, warm the material to 200-250 degrees Fahrenheit to assist it.
Heat Treatment – The 7075 can be annealed at 900 degrees Fahrenheit for approximately 2 hours, followed by a water quench and a precipitation hardening (aging) heat treatment.
Forging – This aluminum can be forged with a temperature ranging from 900 to 700 degrees Fahrenheit. After forging, a heat solution treatment should follow.
Hot Working – To assist in forming the material, warm it to 250 degrees Fahrenheit.
Cold Working – This can be accomplished when in a soft, annealed condition. Further, conventional forming can be used with greater spring-back ability compared to other aluminum alloys.
Annealing – The ideal temperature for annealing this aluminum is 775 degrees Fahrenheit for 3 hours. In addition, its controlled cooling is at 50 degrees Fahrenheit per hour and decreasing down to 500 degrees Fahrenheit from which it can then be air cooled.
Aging – Precipitation strengthening or aging is done at 250 degrees Fahrenheit for about 24 hours and then air cooled for a T6 temper and the T73 temper requires heating to 225 degrees Fahrenheit for 8 hours, which is then followed by 24 hours at 325 degrees Fahrenheit air cooling.
Hardening – This type of aluminum hardens by precipitation heat treatment or aging.
Other Physical Properties – This aluminum has an electrical conductivity to that of 36% of copper.
Aerotech Alloys supplies a wide range of 7075 Aluminum in plate, sheet, rod, bar and tube formations. They work with every customer needs and specifications to improve accuracy and satisfaction.