Alloy 6061 has moderate strength (tensile strength in T6 temper is 310MPa and yield strength is 276MPa), but has excellent corrosion resistance and high plane strain fracture toughness. It is easily welded by the GTA or GMA process, and welds reheat treated with 4043 filler have approximately the same tensile strength as the base metal. Fusion welds have excellent corrosion resistance. Resistance welding is difficult and requires special care.
The plastically stretched T451temper can be exploited to relieve stress in T4. Plates stretch 1.5 to 3%. Rolled or cold-worked bars and rods stretch 1 to 3 percent. No further straightening is required after stretching.
| Main composition | Mg | Si | Cu | Cr | Al |
|---|---|---|---|---|---|
| 6061 | 1 | 0.6 | 0.25 | 0.20 | Balance |
| 6061 composition (wt.%) | Min | Max |
|---|---|---|
| Cr | 0.04 | 0.35 |
| Cu | 0.15 | 0.40 |
| Fe | -- | -- |
| Mg | 0.8 | 1.2 |
| Mn | -- | 0.15 |
| Si | 0.40 | 0.80 |
| Ti | -- | 0.15 |
| Zn | -- | 0.25 |
| Other impurities | ||
| each | -- | 0.05 |
| total | -- | 0.15 |
| Al | Balance | |
Mechanical properties：
| Alloy | T.S. (MPa) | Y.S. (MPa) | Elongation (%) | Density (gcm3) |
|---|---|---|---|---|
| 6061-T6 | 310 | 276 | 12 (thickness 1.59mm) | 2.70 |
Application：
It can be used in bicycle frame tubes, seat tubes, and heavy-duty structures that require high corrosion resistance, such as truck bodies, marine structures, railway tank cars, tubes, etc.
References：
1.AIWT, Aerospace Structure Metals Handbook, Nonferrous Alloys, 6061Al
2.Matweb, datasheet.
