Silicon Carbide
also SiC, Sintered SiC
Silicon Carbide (SiC) is a covalent carbide ceramic supplied to ASTM C1793 and GB/T 10700 in sintered, reaction-bonded (NBSC/SiSiC), CVD and low-resistivity ESD grades.
Reference datasheet — Silicon Carbide is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the Sintered condition
Silicon Carbide tempers and conditions
Silicon Carbide is supplied in 4 conditions, soft to hard. Sintered is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
silicon-infiltrated SiC (SiSiC / RBSiC) | Pick for large, complex near-net-shape parts (kiln beams, burner tubes, armour tiles, wear liners) where cost and size matter more than the 1380 °C free-silicon limit. | 190 | 2,200 HV | 150 W/m·K | ||
SinteredDefault pressureless sintered SiC (SSiC) | Pick for maximum hardness, strength and corrosion resistance — mechanical seal faces, bearings, semiconductor and high-temperature parts. | 250 | 2,500 HV | 120 W/m·K | ||
ESD-Safe | Sintered SiC whose grain-boundary/dopant chemistry is tuned to a controlled dissipative resistivity band (about 1e5–1e9 Ω·cm) so wafer chucks, end-effectors and handling tooling bleed off charge without arcing, while keeping SSiC stiffness, hardness and thermal conductivity. | 2,300 HV | 110 W/m·K | |||
Nitride bonded silicon carbide | Pick for low-cost, thermal-shock-proof refractory shapes — kiln furniture, aluminium-melt riser tubes, degassing lances — where porosity and modest strength are acceptable. | 16 W/m·K |
Supply forms, finishes and certifications
Ways Silicon Carbide is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
CVD | CVD | Coating |
What is Silicon Carbide?
Silicon Carbide (SiC) is a covalent carbide ceramic supplied to ASTM C1793 and GB/T 10700 in sintered, reaction-bonded (NBSC/SiSiC), CVD and low-resistivity ESD grades. Engineers select it for its hardness, 120 W/m·K thermal conductivity, 410 GPa elastic modulus and 1600 °C service limit, in seal faces, wear rings, nozzles, armor tiles and semiconductor components. It is brittle (250 MPa tensile), not weldable, and fired material must be diamond-ground (machinability score 3), so near-net shaping drives cost. Silicon nitride is the nearest alternative when fracture toughness matters more than conductivity. Silicon Carbide has a density of 3.15 g/cm³ (0.114 lb/in³), lighter than 73% of ceramic grades. It melts at 2,730°C (4,946 °F). Silicon Carbide has a tensile strength of 250 MPa (36.3 ksi), stronger than 63% of ceramic grades. The elastic modulus is 410 GPa (59.5 Msi).
What is Silicon Carbide used for?
- Mechanical and pump seal faces
- Slurry pump wear rings and liners
- Sandblast and burner nozzles
- Ceramic armor plates
- Kiln furniture and support beams
- Semiconductor wafer chucks and substrates
- Heat exchanger tubes
- Shaft bearing bushes for chemical pumps
Advantages
- Polishes to a fine finish — 92/100, better than 89% of ceramic grades
- Conducts heat well — 120 W/m·K (69.3 BTU/hr·ft·°F), better than 88% of ceramic grades
- Good corrosion resistance — 92/100, better than 88% of ceramic grades
- High service temperature — 1,600°C (2,912 °F), better than 86% of ceramic grades
Silicon Carbide properties
Typical room-temperature values for Silicon Carbide-Sintered; bars are the position among ceramic grades.
Physical4
Silicon Carbide has a density of 3.15 g/cm³ (0.114 lb/in³), lighter than 73% of ceramic grades. It melts at 2,730°C (4,946 °F).
Mechanical11
Silicon Carbide has a tensile strength of 250 MPa (36.3 ksi), stronger than 63% of ceramic grades. The elastic modulus is 410 GPa (59.5 Msi).
Thermal5
Silicon Carbide is rated for continuous service to 1,600°C (2,912 °F). It conducts heat at 120 W/m·K (69.3 BTU/hr·ft·°F), better than 88% of ceramic grades. Thermal expansion is 4 µm/m·K (2.22 µin/in·°F).
Electrical2
Silicon Carbide has an electrical resistivity of 10 Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (92/100), better than 88% of ceramic grades.
Sustainability4
Producing a kilogram of Silicon Carbide takes about 80 MJ of energy and emits 5.5 kg of CO₂ — less than 67% of ceramic grades. Typical recycled content is 2%.
Manufacturability3
Silicon Carbide's machinability is not recommended (3/100, worse than 95% of ceramic grades).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the ceramic family
Yield strength against density for every ceramic grade FabDigit runs. Silicon Carbide is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Silicon Carbide
Is Silicon Carbide easy to machine?
Green/pre-sintered machining is the economical route; fired SiC needs diamond grinding, lapping or laser/waterjet, and is too electrically variable for reliable EDM except in doped low-resistivity grades.
Can Silicon Carbide be welded?
Not weldable; join by ceramic brazing (Ti/Ag-Cu-Ti active brazes), glass or reaction bonding, or shrink-fit into metal housings with compliant elastomer seats.
Can Silicon Carbide be formed, bent or molded?
Shaped by dry/isostatic pressing, extrusion, slip or gel casting, or injection moulding of feedstock; SiSiC uses a machinable carbon/SiC preform followed by silicon infiltration, allowing large complex near-net shapes.
Silicon Carbide chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| SiCα-SiC (mainly 6H) matrix in the sintered grade | 98 – 99.8 | 99 |
| C (free carbon)sintering aid residue with boron | 0.1 – 1 | 0.5 |
| BB4C/B sintering aid (some grades use Al2O3+Y2O3 instead) | 0.2 – 1 | 0.5 |
| Si (free silicon)sintered grade; 8–15 % in reaction-bonded SiSiC | 0 – 1 | 0.2 |
| Sistoichiometric SiC = 70.05 wt % Si / 29.95 wt % C | balance |
What surface finishes work on Silicon Carbide?
Lapped and polished to mirror finish (Ra ≤ 0.02 µm) for seal and optical faces; can be CVD-SiC coated or Si-impregnated to seal porosity; no plating or painting needed for corrosion protection.
Equivalent designations
Standards and trade names that resolve to Silicon Carbide in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- SiCSintered SiCSSiC
- Similar grades
- C1793GB/T 10700
How much does Silicon Carbide cost?
Silicon Carbide is a high-cost ceramic ($$$$), pricier than about 98% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Silicon Carbide — frequently asked
What is Silicon Carbide used for?
Silicon Carbide is typically used for mechanical and pump seal faces, slurry pump wear rings and liners, sandblast and burner nozzles, ceramic armor plates, kiln furniture and support beams and semiconductor wafer chucks and substrates. In short: extreme wear ceramic.
What is the tensile strength of Silicon Carbide?
Silicon Carbide has a typical tensile strength of 250 MPa (36.3 ksi) — stronger than 63% of ceramic grades. Strength varies by condition: see the 4 listed tempers.
Is Silicon Carbide easy to machine?
Not especially — machinability is rated not recommended (3/100, worse than 95% of ceramic grades). Green/pre-sintered machining is the economical route; fired SiC needs diamond grinding, lapping or laser/waterjet, and is too electrically variable for reliable EDM except in doped low-resistivity grades.
Can Silicon Carbide be welded?
Not weldable; join by ceramic brazing (Ti/Ag-Cu-Ti active brazes), glass or reaction bonding, or shrink-fit into metal housings with compliant elastomer seats.
What surface finishes work on Silicon Carbide?
Lapped and polished to mirror finish (Ra ≤ 0.02 µm) for seal and optical faces; can be CVD-SiC coated or Si-impregnated to seal porosity; no plating or painting needed for corrosion protection.
Can Silicon Carbide be formed, bent or molded?
Shaped by dry/isostatic pressing, extrusion, slip or gel casting, or injection moulding of feedstock; SiSiC uses a machinable carbon/SiC preform followed by silicon infiltration, allowing large complex near-net shapes.
What is the maximum service temperature of Silicon Carbide?
Silicon Carbide is rated for continuous use to about 1,600°C (2,912 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Silicon Carbide cost?
Silicon Carbide is a high-cost ceramic ($$$$), pricier than about 98% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASM Engineered Materials Handbook, Vol. 4: Ceramics and Glasses — ASM International (1991)
- Hexoloy SA / SE Sintered Silicon Carbide Technical Data — Saint-Gobain Ceramics (2023)
- Silicon Carbide (SSiC, SiSiC) Material Properties — CoorsTek (2023)
- Fine Ceramics Technical Data — Silicon Carbide — Kyocera (2022)
- GB/T 16552 / GB/T 4740 series — SAC (China) (2017)
- Materials and the Environment (embodied energy/CO2 data for SiC) — Ashby / Butterworth-Heinemann (2021)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.