5052 aluminum sheet is AL-Mg series alloy aluminum sheet. Magnesium is the main alloying element in the 5052 alloy aluminum sheets. It is the most widely used anti-rust aluminum. This alloy has high strength, especially fatigue resistance: High plasticity and corrosion resistance, can not be strengthened by heat treatment, good plasticity in semi-cold work hardening, low plasticity in cold work hardening, good corrosion resistance, good weldability, poor machinability, and polishable.
Aluminum and magnesium alloys also contain a small amount of manganese, chromium, beryllium, titanium, etc. Except for a small amount of solid solution, most of the manganese in the alloy forms MnAl6.In the 5052 aluminum sheet, the role of chromium is similar to that of manganese, which improves the resistance to stress corrosion cracking, improves the strength of the base metal and the weld, and reduces the tendency of welding cracks, but its content generally does not exceed 0.35%.
1. Annealing texture phenomenon of 5052 aluminum sheet
The deformed metal of the 5052 aluminum sheet not only has a preferred orientation but after annealing, due to a certain orientation relationship between nucleation and growth, a preferred orientation, that is, an annealing texture, generally appears. Annealing texture includes recovery texture, recrystallization texture, and secondary recrystallization texture. In practice, it has been found that metals with deformed texture have three possibilities for texture change when annealed:
(1)Consistent with the deformation texture of the 5052 aluminum sheet. This case includes the recovery texture and a part of the recrystallized texture.
(2)The annealed texture is completely or partially different from the deformed texture. This is the most common cause of recrystallized texture and secondary recrystallized texture. For example, a copper-type deformed texture with a face-centered cubic lattice and an aluminum alloy transforms into a recrystallized cubic texture.
(3)After annealing, the grains are randomly oriented, that is, the deformation texture of the 5052 aluminum sheet disappears, and the annealing texture does not occur, which is rare.
The recovery process mainly involves the formation and growth of sub-crystals, so the recovery texture is the same as the deformation texture. The annealed recrystallized texture is usually different from the deformed texture.
2. Process performance of 5052 aluminum sheet
5052 aluminum sheet has good plasticity in a hot state. The forging and die forging temperature is 420~475°C, and the hot deformation with a deformation rate of 80% is carried out in this temperature range. The cold stamping performance is related to the alloy state. The cold stamping performance of the annealed state is good, followed by the H32 and H34 states, and the H36/H38 state is not good.
The gas welding, arc welding, resistance welding, spot welding, and seam welding performance of the 5052 aluminum sheet are good, and there is a tendency of crystallization cracks during the two argon arc welding. The brazing performance is good, but the soft brazing performance is poor. The strength and plasticity of the weld are high, and the strength of the weld reaches 90%to 95%of the strength of the base metal. However, the air tightness of the weld is not high. It is recommended to use an alloy as the solder, which can improve its air tightness and eliminate the tendency of cracks.
The machinability of the 5052 aluminum sheet in the annealed state is not good, but it is improved in the cold work-hardened state.