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to Wrought aluminum alloys
Dr. Dmitri Kopeliovich
According to the Wrought aluminum alloys designation system, alloys of this series are designated 6xxx.
This group includes magnesium (Mg) and silicon (Si) as the major alloying elements.
Copper (Cu), manganese (Mn), chromium (Cr), zinc (Zn), boron (B), lead (Pb) and bismuth (Bi) may be added to the alloys of 6xxx series as minor alloying elements.
Aluminum-magnesium-silicon alloys are heat-treatable.
Solution treatment followed by either artificial or natural aging allows considerable increasing the yield strength (3-5 times). Ductility of the alloy decreases as a result of the heat treatment.
Hardening of the alloys from this group is achieved due to precipitation of the phase Mg2Si occurring during aging.
This phase has a fixed ratio between the elements contents (valence compound), therefore amounts of magnesium and silicon in 6xxx alloys are balanced according to this ratio or with an excess of silicon.
Alloys of this series possess high mechanical strength combined with good formability and corrosion resistance.
Excess of silicon enhances effect of precipitation hardening of the alloys, but decreases their ductility because of segregation of silicon at the regions of grain boundaries. This adverse effect of silicon may be diminished by addition of chromium and manganese depressing recrystallization during solution treatment.
Temperature of artificial aging of 6xxx alloys is 320-360°F (160-182°C).
Aluminum-magnesium-silicon alloys (6xxx series) are used in aircraft and automotive applications, in architectural applications and as structural material.
| Designation | Si,% | Cu,% | Mn,% | Mg,% | Cr,% | Others,% |
|---|---|---|---|---|---|---|
| 6003 | 0.35-1.0 | 0.10 max. | 0.8 max. | 0.8-1.5 | 0.35 max. | - |
| 6005 | 0.6-0.9 | 0.10 max. | 0.10 max. | 0.4-0.6 | 0.10 max. | - |
| 6053 | * | 0.10 max. | - | 1.1-1.4 | 0.15-0.35 | - |
| 6061 | 0.4-0.8 | 0.15-0.40 | 0.15 max. | 0.8-1.2 | 0.04-0.35 | - |
| 6063 | 0.2-0.6 | 0.10 max. | 0.10 max. | 0.45-0.9 | 0.10 max. | - |
| 6066 | 0.9-1.8 | 0.7-1.2 | 0.6-1.1 | 0.8-1.4 | 0.40 max. | - |
| 6070 | 1.0-1.7 | 0.15-0.40 | 0.4-1.0 | 0.50-1.2 | 0.10 max. | - |
| 6101 | 0.3-0.7 | 0.10 max. | 0.03 max. | 0.35-0.8 | 0.03 max. | B 0.06% max. |
| 6105 | 0.6-1.0 | 0.10 max. | 0.10 max. | 0.45-0.8 | 0.10 max. | - |
| 6151 | 0.6-1.2 | 0.35 max. | 0.20 max. | 0.45-0.8 | 0.15-0.35 | - |
| 6162 | 0.4-0.8 | 0.20 max. | 0.10 max. | 0.7-1.1 | 0.10 max. | - |
| 6201 | 0.5-0.9 | 0.10 max. | 0.03 max. | 0.6-0.9 | 0.03 max. | B 0.06% max. |
| 6253 | * | 0.10 max. | - | 1.0-1.5 | 0.04-0.35 | Zn 1.6-2.4% |
| 6262 | 0.4-0.8 | 0.15-0.40 | 0.15 max. | 0.8-1.2 | 0.04-0.14 | Pb and Bi 0.4-0.7% each |
| 6351 | 0.7-1.3 | 0.10 max. | 0.4-0.8 | 0.4-0.8 | - | - |
| 6463 | 0.2-0.6 | 0.20 max. | 0.05 max. | 0.4-0.9 | - | - |
| 0.2-0.5 | 0.15-0.40 | 0.10 max. | 0.4-0.8 | - | - |
*- Silicon content = 0.40..0.7 x actual magnesium content.
aluminum concentration - balance
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