Silicon carbide (SiC) crucibles offer several advantages over traditional crucible materials like graphite, clay-graphite, or quartz, especially in high-temperature and reactive environments. Here are the key benefits of using silicon carbide crucibles:
1. High Thermal Conductivity
SiC has excellent thermal conductivity (≈120 W/m·K), ensuring rapid and uniform heating.
Reduces thermal stress and cracking compared to materials like alumina or quartz.
2. Exceptional Thermal Shock Resistance
SiC can withstand rapid temperature changes without cracking, making it ideal for processes involving sudden heating or cooling.
3. High-Temperature Stability
Operates effectively at temperatures up to 1600°C (in inert/reducing atmospheres) and up to 1400°C in oxidizing conditions.
Outperforms graphite (which oxidizes above 600°C) and alumina (softens at high temps).
4. Superior Chemical Resistance
Resists corrosion from molten metals (Al, Cu, Zn), salts, and slags.
More durable than graphite when exposed to reactive metals like aluminum or silicon.
5. Mechanical Strength & Durability
High hardness (~9.5 Mohs) and compressive strength reduce wear and deformation.
Longer lifespan than clay-graphite or quartz crucibles.
6. Oxidation Resistance
Forms a protective SiO₂ layer in air, preventing rapid degradation (unlike graphite, which erodes).
7. Non-Wetting Surface
Minimizes sticking of molten metals, allowing easier pouring and cleaning.
8. Energy Efficiency
Faster heat transfer reduces energy consumption in melting applications.
TYPICAL CHEMICAL ANALYSIS | TYPICAL PHISICAL PROPERTIES | ||
SiC | ≥98% | Hardness: | Mohs:9.15 |
SiO2 | ≤1% | Melting Point: | Sublimes at 2250 ℃ |
H2O3 | ≤0.5% | Maximum service temperature: | 1900℃ |
Fe2O3 | ≤0.3% | Specific Gravity: | 3.2-3.45 g/cm3 |
F.C | ≤0.3% | Bulk density(LPD): | 1.2-1.6 g/cm3 |
Magnetic content | ≤0.02% | Color: | Black |
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| Particle shape: | Hexagonal |
Applications of SiC Crucibles:
Metal Melting & Casting (Al, Cu, Zn, precious metals)
Semiconductor Processing (Si, GaAs crystal growth)
Glass & Ceramic Production
High-Temperature Chemical Reactions
SiC crucibles are ideal for high-temperature, high-performance applications where durability, thermal shock resistance, and chemical stability are critical. They outperform traditional crucible materials in harsh environments but come at a higher initial cost.
