There are many kinds of aluminium alloy used in aircraft. Nowadays, the aluminum alloys used in aviation aircraft structures in different countries worldwide are manly high strength 2 series(2024, 2014, 2219, 2524, 2017,2a12, etc.) and super hard 7xxx aluminum(7075, 7475, 7050, 7475, 7068, 7a04,etc.). Some 5 series( 5052, 5086, 5a06,etc.) and 6 series (6061, 6063, 6082,etc.) are also used for airplane seat and interior decoration.