Silicon Carbide · print state
Silicon Carbide Reaction Bonded
Properties of the Reaction Bonded condition, compared with the other Silicon Carbide tempers.
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.
What is Silicon Carbide Reaction Bonded?
Silicon Carbide Reaction Bonded is Silicon Carbide in the Reaction Bonded condition — 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. Silicon Carbide Reaction Bonded has a tensile strength of 190 MPa (27.6 ksi), stronger than 58% of ceramic grades. The elastic modulus is 380 GPa (55.1 Msi). Silicon Carbide Reaction Bonded has a density of 3.08 g/cm³ (0.111 lb/in³), lighter than 74% of ceramic grades. It melts at 2,730°C (4,946 °F). Sintered is the default condition FabDigit quotes; Reaction Bonded is available on request or by drawing note.
Advantages
- Conducts heat well — 150 W/m·K (86.7 BTU/hr·ft·°F), better than 93% of ceramic grades
- Polishes to a fine finish — 92/100, better than 87% of ceramic grades
- High service temperature — 1,380°C (2,516 °F), better than 77% of ceramic grades
Silicon Carbide Reaction Bonded properties
Typical room-temperature values for Silicon Carbide Reaction Bonded — 17 properties are specific to this condition; the rest are grade-level values shared by every Silicon Carbide temper. Each bar shows where the value sits among the ceramic grades in FabDigit's library — further right is higher.
Physical4
Silicon Carbide Reaction Bonded has a density of 3.08 g/cm³ (0.111 lb/in³), lighter than 74% of ceramic grades. It melts at 2,730°C (4,946 °F).
Mechanical11
Silicon Carbide Reaction Bonded has a tensile strength of 190 MPa (27.6 ksi), stronger than 58% of ceramic grades. The elastic modulus is 380 GPa (55.1 Msi).
Thermal5
Silicon Carbide Reaction Bonded is rated for continuous service to 1,380°C (2,516 °F). It conducts heat at 150 W/m·K (86.7 BTU/hr·ft·°F), better than 93% of ceramic grades. Thermal expansion is 4.3 µm/m·K (2.39 µin/in·°F).
Electrical2
Silicon Carbide Reaction Bonded has an electrical resistivity of 0.05 Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (85/100), better than 68% of ceramic grades.
Sustainability4
Producing a kilogram of Silicon Carbide Reaction Bonded takes about 80 MJ of energy and emits 5.5 kg of CO₂ — less than 66% of ceramic grades. Typical recycled content is 2%.
Manufacturability3
Silicon Carbide Reaction Bonded's machinability is not recommended (5/100, worse than 58% of ceramic grades).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other Silicon Carbide tempers and conditions
Silicon Carbide is also supplied in 4 other conditions. The full side-by-side table is on the Silicon Carbide overview.
- SinteredDefaultPick for maximum hardness, strength and corrosion resistance — mechanical seal faces, bearings, semiconductor and high-temperature parts.250 MPa tensile
- Reaction BondedPick 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 MPa tensile
- CVDUltra-pure, fully dense theoretical-density beta-SiC grown by chemical vapor deposition; zero porosity, no sintering aids, highest thermal conductivity and best polishability of all SiC forms — used for semiconductor process chambers, susceptors, mirrors and optics.2,500 HV
- ESDSintered 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
- NBSCPick for low-cost, thermal-shock-proof refractory shapes — kiln furniture, aluminium-melt riser tubes, degassing lances — where porosity and modest strength are acceptable.12 properties
Working with Silicon Carbide Reaction Bonded
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.
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.
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 | — |
Silicon Carbide Reaction Bonded — frequently asked
What is Silicon Carbide Reaction Bonded used for?
Silicon Carbide Reaction Bonded 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 Reaction Bonded?
Silicon Carbide Reaction Bonded has a typical tensile strength of 190 MPa (27.6 ksi) — stronger than 58% of ceramic grades. Strength varies by condition: see the 5 listed tempers.
Is Silicon Carbide Reaction Bonded easy to machine?
Not especially — machinability is rated not recommended (5/100, worse than 58% 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 Reaction Bonded 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 Reaction Bonded?
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 Reaction Bonded 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 Reaction Bonded?
Silicon Carbide Reaction Bonded is rated for continuous use to about 1,380°C (2,516 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in Silicon Carbide Reaction Bonded?
Yes — Silicon Carbide Reaction Bonded is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.