What is molten aluminum used for?
Important note: Aluminum alloys melt over a temperature range, not a single melting‑point value.
Melting point of pure aluminum (99.99%): 660.32 °C.
Wrought Aluminum Alloys (Series 1‑7, for extrusion, rolling & forging)
1xxx Series (Pure Aluminum, 1050, 1100)
Solidus: 643 °C｜Liquidus: 657 °C
Narrow melting range. High electrical & thermal conductivity. Typical melting temperature: 720‑740 °C.
2xxx Series (Al‑Cu, 2024, 2014, high‑strength aerospace grade)
2024: Solidus: 502 °C｜Liquidus: 638 °C
Wide mushy zone. Low solidus temperature, high risk of incipient melting / over‑burning. Strict temperature control required for melting and heat treatment.
3xxx Series (Al‑Mn, 3003, 3004, for cans & heat exchangers)
3003: Solidus: 640 °C｜Liquidus: 654 °C
Very narrow melting interval. Manganese has little influence on melting temperature. Low over‑burning risk.
5xxx Series (Al‑Mg, 5052, 5083, marine corrosion‑resistant alloys)
‑ 5052: Solidus: 607 °C｜Liquidus: 649 °C
‑ 5083: Solidus: 550 °C｜Liquidus: 645 °C
Higher magnesium content lowers solidus temperature. Prevent oxidation and burning during melting high‑Mg grades.
6xxx Series (Al‑Mg‑Si, 6061, 6063, general extrusion & construction alloys)
‑ 6061: Solidus: 582 °C｜Liquidus: 652 °C
‑ 6063: Solidus: 580 °C｜Liquidus: 645 °C
Most widely used wrought aluminum alloys. Typical melting range 720‑750 °C.
7xxx Series (Al‑Zn‑Mg‑Cu, 7075, ultra‑high‑strength aerospace)
7075: Solidus: 477 °C｜Liquidus: 635 °C
Extremely wide melting range. Lowest solidus among common aluminum alloys. Very sensitive to over‑heating; tight temperature control is mandatory.
Cast Aluminum Alloys (Sand casting, gravity casting & die‑casting)
Silicon reduces melting temperature and improves casting fluidity.
‑ A356 (AlSi7Mg, wheel hub, cylinder head): Solidus: 557 °C｜Liquidus: 613 °C
‑ A380 die‑cast alloy: Solidus: 515 °C｜Liquidus: 585 °C
‑ ADC12 die‑casting alloy: Solidus: 500 °C｜Liquidus: 580 °C
‑ ZL102 (Al‑Si12 eutectic alloy): Eutectic temperature 577 °C, excellent casting fluidity.
Practical melting temperature for cast alloys: 700‑760 °C; do not exceed 780 °C to minimize hydrogen absorption and oxidation.
Summary Table (Unit: °C)
| Alloy Series |
Typical Grade |
Solidus |
Liquidus |
Remarks |
| 1xxx Pure Al |
1100 |
643 |
657 |
Narrow melting range |
| 2xxx Al‑Cu |
2024 |
502 |
638 |
Risk of over‑burning |
| 3xxx Al‑Mn |
3003 |
640 |
654 |
Very narrow interval |
| 5xxx Al‑Mg |
5083 |
550 |
645 |
Mg reduces solidus |
| 6xxx Al‑Mg‑Si |
6061 |
582 |
652 |
General‑purpose extrusion |
| 7xxx Al‑Zn‑Mg‑Cu |
7075 |
477 |
635 |
Very low solidus, strict temperature control |
| Cast alloy |
A356 |
557 |
613 |
Sand / gravity casting |
| Die‑cast alloy |
ADC12 |
500 |
580 |
High‑pressure die casting |
Industrial Melting Practical Notes
- Operating melting temperature should be liquidus +50~100 °C to secure proper fluidity.
- Grades with low solidus such as 7075 and 2024 shall never be over‑heated. Incipient melting will permanently damage material properties.
- Alumina (Al₂O₃) skin melts at ~2072 °C. It remains solid in molten aluminum, so dross removal is necessary.
- Higher silicon content lowers liquidus temperature and improves casting fluidity.
- Values above are typical reference data. Actual temperatures shift slightly with compositional variation. Always refer to official material datasheets for formal production.
