① 7075 is a cold-treated forged alloy with high strength, far superior to mild steel. 7075 is one of the strongest commercial alloys. Ordinary corrosion resistance, good mechanical properties and anodic reaction. Fine grains make deep drilling performance better, tool wear resistance enhanced, and thread rolling more different.

② It belongs to the Al-Zn-Mg-Cu series of super-hard aluminum. This alloy has been used in the aircraft manufacturing industry since the late 1940s and is still widely used in the aviation industry. It is an ultra-high strength deformed aluminum alloy. Its characteristics are good plasticity after solution treatment, particularly good heat treatment strengthening effect, high strength below 150°C, and particularly good low-temperature strength; poor welding performance; tendency to stress corrosion cracking; need to be aluminum-clad or other protective treatments before use. Double-stage aging can improve the alloy's ability to resist stress corrosion cracking. The plasticity in the annealed and just quenched state is slightly lower than that of 2A12 in the same state. It is slightly better than 7A04. The static fatigue and notch sensitivity of the plate and the stress corrosion resistance are better than 7A04.