Material Overview
Silicon Carbide (SiC) is a high-performance advanced ceramic material renowned for its exceptional hardness (second only to diamond), thermal stability (up to 1,650°C), and resistance to wear, corrosion, and oxidation. Silicon carbide ceramics are composed of silicon and carbon atoms bonded together in a covalent lattice. Due to their unique combination of mechanical and thermal properties, they are excellent high-temperature structural ceramic materials. Their most basic function is as refractory materials and abrasives, such as water nozzle bricks in steelmaking, furnace linings, kiln furniture, and grinding wheels. Later, their functions were expanded to include aerospace, semiconductor manufacturing, energy systems, and industrial machinery, where they are used as high-temperature structural components or heating elements.
Technical Data & Selection
RBSiC vs. SSiC: Selecting the Optimal Process for Your Application
| Key Property | Reaction Bonded SiC (RBSiC) | Sintered SiC (SSiC) | What This Means for Your Design |
| Max. Service Temp. | ~1,300°C (in air) | ~1,650°C (in air) | For environments with sustained extreme heat, SSiC is superior. |
| Thermal Conductivity | High (~150 W/m·K) | High (~120-150 W/m·K) | Both are excellent for heat dissipation. |
| Fracture Toughness | Medium-High(4~5MPa.m1/2) | Medium(4MPa.m1/2) | RBSiC often better suits parts facing mechanical shock. |
| Complex Shape Forming | Good | Fair | RBSiC is preferred for large or highly intricate near-net-shape parts. |
Silicon Carbide Productions
Silicon carbide is also known as “superhard ceramic” and is a common material for ceramic valve seats, ceramic plungers, ceramic nozzles, and ceramic wear parts.
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Silicon Carbide Sheet -
Silicon Carbide Seal -
Silicon Carbide Insert -
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Silicon Carbide Parts
Related Materials
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Alumina ceramics are advanced ceramics with excellent comprehensive properties, and they were researched early, are the most widely used, and are the most mature.
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Zirconia ceramics are second only to alumina ceramics in terms of applicability and are very important advanced ceramics for structural applications.
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Aluminum nitride ceramics are advanced ceramics with high thermal conductivity and insulation, and are often used in electronic packaging substrates and heat dissipation components.
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Silicon nitride ceramics are high-strength, lightweight, and thermally shock resistant advanced ceramics commonly used in bearings and turbine components.
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Steatite ceramics are low-cost, high-frequency insulators, and have low mechanical strength, making them suitable for use in general equipment parts.
Key Features
- Ultra-High Hardness: Mohs hardness of 9.5, ideal for abrasive environments like mining and cutting tools.
- Thermal Conductivity: Ranges from 120–150 W/mK, enabling efficient heat dissipation in high-power electronics.
- Chemical Inertness: Resists acids (e.g., HCl, H₂SO₄), alkalis, and molten metals, ensuring longevity in corrosive settings.
- Oxidation Resistance: Maintains structural integrity at 1,600°C in air due to a protective SiO₂ surface layer.
Applications
- Semiconductor: Wafer handling arms, plasma etching components, and susceptors for CVD reactors.
- Energy: Heat exchangers, burner nozzles, and turbine blades in gas turbines.
- Industrial: Wear-resistant liners for pumps, seals, and valves in chemical processing.
- Automotive: Brake discs and bearings for electric vehicles (EVs) due to lightweight and thermal stability.
Manufacturing Techniques
- Hot Pressing: Produces ultra-dense ceramics (>99% density) for high-stress applications.
- CNC /Grinding: For precise dimensional tolerance.
- Additive Manufacturing: 3D-printed SiC parts samples for complex geometries, with our supporting partners’ help.
Silicon carbide outperforms metals due to its ultra-high thermal stability (1,650°C vs. 500°C for stainless steel) and oxidation resistance. For example, SiC burner nozzles in gas turbines reduce maintenance costs by 70% compared to nickel alloys, while their low thermal expansion (4.0×10⁻⁶/°C) prevents cracking under thermal cycling.
Silicon carbide ceramics have excellent wear resistance, and their hardness is second only to diamond. They can effectively resist high-speed particle erosion, mechanical friction, and impact wear. Under the same working conditions, their wear resistance far exceeds that of steel and traditional oxide ceramics such as alumina (Al2O3) and zirconia (ZrO2), and their service life can be extended several times. They are especially suitable for harsh wear environments such as mining, metallurgy, and electricity, greatly reducing the frequency and cost of equipment maintenance.
- Chemical Processing: SiC-lined pipes transport corrosive media (e.g., sulfuric acid) with a service life exceeding 5 years, reducing replacement frequency by 80%.
- Semiconductor: SiC components resist plasma erosion in etching chambers, extending tool lifespan by 50%.
- Energy: Molten salt reactors use SiC seals to prevent leakage in high-temperature, corrosive environments.
The core advantages of RBSC lie in its exceptional manufacturability and cost-effectiveness. The process involves silicon melt infiltrating a carbon preform, resulting in minimal sintering distortion. This allows for the production of very large or highly complex near-net-shape components with lower post-machining costs. Additionally, the presence of a small amount of residual silicon provides improved thermal shock resistance and slightly higher fracture toughness, making it ideal for large structural wear/corrosion-resistant parts like large bushings, chemical valve bodies, and kiln rollers.
It depends on the failure mode. Flexural Strength determines the initial failure point under bending load in an ideal, flaw-free state. Fracture Toughness describes the material’s ability to resist crack propagation and catastrophic fracture when inevitable micro-cracks or defects exist. For components under dynamic loads like thermal cycling or mechanical shock, high fracture toughness (e.g., in RBSiC) is often the more critical guarantee of reliability, preventing sudden brittle failure.