Such as 6061 and 7075, are commonly used materials, with a density of 2.7-2.8g/cm³, very light, only about 40% of steel. High strength, but poor fatigue resistance and high temperature resistance, usually used in various casings or structural components. The frame of your phone, camera, or computer may be made from a single piece of aluminum CNC machined. Aluminum alloy also has good corrosion resistance, the dense aluminum oxide layer on the surface can effectively isolate oxygen, water, and weak acid/alkali environments from corrosion, but still requires anodizing or painting for protection.
