Melting Point of Metals
The melting point of a metal is the temperature at which it changes from a solid (crystalline) state to a liquid state under standard atmospheric pressure (1 atm, or 101.325 kPa). At this temperature, the solid and liquid phases of the metal coexist in thermodynamic equilibrium.
Different metals have different melting points due to their atomic structure and bonding. For example:
- Tungsten (W): Melting point 3422°C (highest among metals, used in high-temperature applications like light bulb filaments and rocket nozzles).
- Iron (Fe): Melting point 1538°C (widely used in construction and manufacturing).
- Titanium (Ti): Melting point 1668°C (high strength, low density, used in aerospace and medical implants).
- Zinc (Zn): Melting point 419.5°C (commonly used in galvanized steel and batteries).
- Lead (Pb): Melting point 327.5°C (low melting point, used in radiation shielding and solder).
- Tin (Sn): Melting point 231.9°C (used in soldering and food packaging).
Alloys usually have different melting points than pure metals:
- Brass (copper-zinc alloy): Melting point 900–940°C (varies with zinc content).
- Nickel-based superalloys (e.g., Inconel): Melting point 1350–1430°C (used in jet engines and extreme environments).
The difference in melting points is mainly determined by metallic bond strength, atomic radius, and crystal structure. For example, tungsten’s high melting point comes from its strong metallic bonds and tightly packed crystal structure, while lead’s low melting point is due to its larger atomic size and weaker bonding.
Here’s a table of melting points for common metals and alloys sorted from lowest to highest melting point (in English):
| Metal/Alloy Name | Melting Point (°C) | Melting Point (°F) | Type | Notes |
|---|---|---|---|---|
| Mercury (Hg) | -39 | -38 | Pure Metal | Liquid at room temperature |
| Solder (63/37) | 183 | 361 | Alloy | Tin (63%) + Lead (37%) |
| Solder (60/40) | 190 | 374 | Alloy | Tin (60%) + Lead (40%) |
| Lead (Pb) | 327 | 621 | Pure Metal | Used in batteries, radiation shielding |
| Tin (Sn) | 232 | 450 | Pure Metal | Common in soldering |
| Zinc (Zn) | 419 | 786 | Pure Metal | Key component of galvanized steel |
| Aluminum (Al) | 660 | 1220 | Pure Metal | Lightweight, high conductivity |
| Brass | 900-940 | 1652-1724 | Alloy | Copper (60-80%) + Zinc |
| Silver (Ag) | 961 | 1762 | Pure Metal | High conductivity, precious metal |
| Copper (Cu) | 1085 | 1985 | Pure Metal | Excellent thermal conductor |
| Bronze | 950-1050 | 1742-1922 | Alloy | Copper (88%) + Tin (12%) |
| Gold (Au) | 1064 | 1947 | Pure Metal | Corrosion-resistant, highly malleable |
| Mild Steel | 1370-1510 | 2500-2750 | Alloy | Iron + Carbon (<0.3%) |
| Nickel (Ni) | 1455 | 2651 | Pure Metal | Heat and corrosion resistant |
| Stainless Steel (304) | 1400-1450 | 2552-2642 | Alloy | Iron + Chromium (18%) + Nickel (8%) |
| Cast Iron | 1130-1300 | 2066-2372 | Alloy | Iron + Carbon (2-4%) |
| Titanium (Ti) | 1668 | 3034 | Pure Metal | High strength-to-weight ratio |
| Iron (Fe) | 1538 | 2800 | Pure Metal | Foundational industrial metal |
| Nickel Alloy (Inconel) | 1390-1425 | 2534-2600 | Alloy | Nickel + Chromium + Iron |
| Tungsten (W) | 3422 | 6192 | Pure Metal | Highest melting point of all metals |
