Introduction: The Power of Silicon Carbide
Silicon carbide (SiC) stands out as one of the most advanced ceramic materials available today,
renowned for its exceptional strength, thermal stability, and durability. Whether used in
high-temperature furnaces, power electronics, or abrasive environments, SiC provides unmatched
performance where traditional materials fail. This page offers a detailed breakdown of its chemical
and physical characteristics—ideal for engineers, manufacturers, and technical buyers seeking a
dependable high-performance material.
Chemical Properties of Silicon Carbide
- Chemical Stability: SiC is chemically inert to most acids and bases. However,
it is susceptible to reactions with molten alkalis and certain metal oxides at elevated
temperatures.
- Reaction Temperatures: Stable in inert or reducing atmospheres up to
approximately 1,500°C.
- Typical Impurities: Trace amounts of unreacted carbon (C), silica (SiO₂),
silicon (Si), iron (Fe), aluminum (Al), and calcium (Ca).
- Molecular Composition: Molecular weight is 40.096, consisting of 29.95% carbon
and 70.05% silicon by mass.
Physical Properties of Silicon Carbide
Hardness
- Mohs Scale: 9–10
- Knoop Hardness: 25,000–30,000 N/mm²
Thermal Conductivity
| Temperature |
Thermal Conductivity (W/cm·°C) |
| 20°C |
0.41 |
| 1000°C |
0.21 |
Linear Thermal Expansion
| Temperature Range |
Expansion Coefficient (per °C) |
| 20–1000°C |
5.1 × 10⁻⁶ /°C |
| 20–2000°C |
5.8 × 10⁻⁶ /°C |
Specific Heat Capacity
| Temperature |
Specific Heat (J/g·°C) |
| 25°C |
0.67 |
| 1000°C |
1.26 |
Density Characteristics
- Specific Density: ~3.21 g/cm³
- Bulk Density: 0.5–1.7 g/cm³ depending on size and compaction
Melting and Decomposition Point
Silicon carbide does not melt under normal conditions. Dissociation begins around 2,300°C, making it
ideal for high-heat applications.
Applications & Thermal Stability
Silicon carbide is used in:
- Abrasives and cutting tools
- Heat exchangers and kiln furniture
- Semiconductor and power electronics
- Armor materials and bulletproof ceramics
Technical Summary Table: Silicon Carbide Standard Properties
| Property |
Value/Range |
| Mohs Hardness |
9–10 |
| Knoop Hardness |
25,000–30,000 N/mm² |
| Thermal Conductivity (20°C) |
0.41 W/cm·°C |
| Thermal Conductivity (1000°C) |
0.21 W/cm·°C |
| Thermal Expansion (20–1000°C) |
5.1 × 10⁻⁶ /°C |
| Specific Heat (25°C) |
0.67 J/g·°C |
| Specific Density |
3.21 g/cm³ |
| Bulk Density |
0.5–1.7 g/cm³ |
| Dissociation Temperature |
~2300°C |
| Chemical Composition |
29.95% C, 70.05% Si |
Why Choose Our Silicon Carbide Materials?
- ✅ Customizable properties
- ✅ High-purity grades available
- ✅ Global delivery
- ✅ Responsive technical support
FAQs About Silicon Carbide Properties
- Is silicon carbide harder than steel?
Yes, it is significantly harder than
steel with a Mohs rating close to diamond.
- Can silicon carbide handle extreme heat?
Yes. Stable up to 1500°C, starts
dissociating around 2300°C.
- Is silicon carbide a conductor?
It’s a semiconductor with high thermal but
low electrical conductivity unless doped.
- Does silicon carbide rust?
No, it is chemically stable and resistant to
corrosion and oxidation.
- Can silicon carbide be used in electronics?
Yes, it's used in power
electronics for its wide bandgap and high efficiency.
- What's the difference between black and green SiC?
Black SiC is tougher and
used in abrasives; green SiC is purer, for electronics and polishing.
