2A12 aluminum alloy is a kind of high-strength hard aluminum, which can be heat-treated and strengthened; 2A12 aluminum alloy has good spot weldability, and there is a tendency to form intergranular cracks when using gas welding and argon arc welding; 2A12 aluminum alloy can be cut after cold work hardening Performance is still good. The corrosion resistance is not high, and the anodizing treatment and painting method or the surface is coated with an aluminum layer to improve the corrosion resistanceIt is the most commonly used super-hard aluminum, a high-strength alloy that can be heat treated and strengthened. It is usually used in the quenching artificial aging state. At this time, the strength is much higher than that of the general hard aluminum, but the plasticity is low; the extruded semi-finished product and the aluminum-clad plate which are not too thick in cross section have good corrosion resistance and tend to stress concentration. The spot weldability is good, the gas welding is poor, and the machinability is good after heat treatment and low in the annealed state.
It is an Al-Zn-Mg-Cu ultra-high-strength aluminum alloy, also known as super-hard aluminum. It is a mature, long-lasting and widely used alloy in super-hard aluminum. High strength, good heat treatment strengthening effect, moderate plasticity under annealing and new quenching conditions; unlike hard aluminum, the corrosion resistance under artificial aging is better than that of natural aging, and the natural aging process is slow, requiring 3 After the month, the age hardening peak can be reached, so 7A04 is used in the quenching artificial aging state. The disadvantage is that the stability of the structure is not high, the low-frequency fatigue strength is low, and there is a tendency of stress corrosion cracking. Good spot weldability of alloys, poor gas welding, good machinability after heat treatment, but poor machinability after annealing.

Mechanical Properties