7-series aluminum alloys are widely used in aerospace and aviation, and are also called aviation aluminum.
Mainly zinc, but sometimes a small amount of magnesium and copper are added. Among them, super-hard aluminum alloys contain zinc, lead, magnesium and copper alloys close to the hardness of steel. The extrusion speed is slower than that of the 6 series alloy, and the welding performance is good. 7005 and 7075 are the highest grades in the 7 series and can be strengthened by heat treatment.
Applications: aviation, rockets, propellers, aviation spacecraft. 7005 Extruded material, used to manufacture welded structures that require both high strength and high fracture toughness, such as trusses, rods, and containers of transportation vehicles; large heat exchangers, and no solid solution treatment after welding Parts.
7039: Freezer containers, cryogenic equipment, fire-fighting equipment, military equipment, armor plates, missile installations;
7049: Used for forging parts that have the same static strength as 7079-T6 alloy and require high resistance to stress corrosion cracking, such as aircraft and missile parts. The fatigue performance of the parts is roughly equal to that of 7075-T6 alloy, but the toughness is slightly higher;
7050: Extruded parts, free forgings and die forgings for aircraft structural parts. The requirements for the manufacture of such parts for the alloy are: high resistance to spalling corrosion, stress corrosion cracking, fracture toughness and fatigue resistance;
7075: Used to manufacture aircraft structures, which require high-strength structural parts and mold manufacturing with high strength and strong corrosion resistance;
7175: High-strength structure used for forging aircraft. T736 material has good comprehensive properties, that is, high strength, spalling corrosion resistance and stress corrosion cracking resistance, fracture toughness, and fatigue strength;
7178: Parts and components that require high compressive yield strength for the manufacture of aerospace vehicles;
7475: Aluminum-clad and non-aluminum-clad plates for the fuselage, wing skeletons, stringers, etc. Other parts that must have both high strength and high fracture toughness;
Features: good plasticity after solution treatment, particularly good heat treatment strengthening effect, high strength below 150℃, and particularly good low temperature strength; poor welding performance; stress corrosion cracking tendency; need to be coated with aluminum or other protective treatments use.