Features and scope of application:
2A11 aluminum alloy is the earliest hard aluminum, generally called standard hard aluminum, with medium strength. It has good plasticity in annealing, quenching and hot state. It can be heat-treated and strengthened. It can be used in quenching and natural aging conditions. The weldability is good, and there is a tendency to crack when performing gas welding and argon arc welding; the cutting is good in the quenching aging state and is poor in the annealing state.
chemical composition:
| Al | Si | Cu | Mg | Zn | Mn | Ti | Ni | Fe | Fe + Ni |
| balance | ≤0.7 | 3.8 - 4.8 | 0.40～0.8 | ≤ 0.30 | 0.40 - 0.8 | ≤ 0.15 | ≤ 0.10 | 0-0.7 | 0-0.7 |
Note: single: ≤ 0.05; total: ≤ 0.10
Mechanical properties:
Tensile strength σb (MPA): ≥370
Yield strength σ0.2 (MPA): ≥215
Elongation δ5 (%): ≥12 Note: Longitudinal mechanical properties of bar at room temperature
Heat treatment specification:
1) Homogenization annealing: heating 480 ~ 495 ° C; holding 12 ~ 14h; furnace cooling.
2) Complete annealing: heating 390 ~ 430 ° C; holding time 30 ~ 120min; air cooling.
3) Rapid annealing: heating 350 ~ 370 ° C; holding time is 30 ~ 120min; air cooling.
4) Quenching and aging: quenching 495 ~ 510 ° C, water cooling; artificial aging 155 ~ 165 ° C, 6 ~ 10h, air cooling; natural aging: room temperature 96h.
