Aluminum Alloy 7075

Aluminum Alloy 7075

7075 aluminum alloy (AA7075) is an aluminum alloy with zinc as the main alloy element. It has excellent mechanical properties, showing good ductility, high strength, toughness and good fatigue resistance. It is more susceptible to embrittlement than many other aluminum alloys due to the presence of microscopic segregation, but its corrosion resistance is significantly better than that of the 2000 series alloys. It is one of the most commonly used aluminum alloys in high-stress structural applications and has been widely used in aircraft structural components.

The composition of 7075 aluminum alloy roughly includes 5.6% to 6.1% zinc, 2.1% to 2.5% magnesium, 1.2% to 1.6% copper, and less than 0.5% of silicon, iron, manganese, titanium, chromium and other metals. It comes in various statuses, some of them are 7075-0, 7075-T6, 7075-T651.

The first 7075 was secretly developed by the Japanese company Sumitomo Metal in 1935, but Alcoa reverse-engineered it in 1943 after examining a captured Japanese aircraft. 7075 was standardized in 1945 for aerospace use. 7075 was eventually used in airframe production for the Imperial Japanese Navy.