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Silicon Carbide · grade

Silicon Carbide NBSC

Properties of the NBSC condition, compared with the other Silicon Carbide tempers.

Pick for low-cost, thermal-shock-proof refractory shapes — kiln furniture, aluminium-melt riser tubes, degassing lances — where porosity and modest strength are acceptable.

CNC machiningHigh cost $$$$

What is Silicon Carbide NBSC?

Silicon Carbide NBSC is Silicon Carbide in the NBSC grade — pick for low-cost, thermal-shock-proof refractory shapes — kiln furniture, aluminium-melt riser tubes, degassing lances — where porosity and modest strength are acceptable. Silicon Carbide NBSC has a tensile strength of 250 MPa (36.3 ksi), stronger than 63% of ceramic grades. The elastic modulus is 100 GPa (14.5 Msi). Silicon Carbide NBSC has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 79% of ceramic grades. It melts at 2,730°C (4,946 °F). Sintered is the default condition FabDigit quotes; NBSC is available on request or by drawing note.

Advantages

  • Polishes to a fine finish — 92/100, better than 87% of ceramic grades
  • Easy to machine — 15/100, better than 83% of ceramic grades
  • High service temperature — 1,500°C (2,732 °F), better than 81% of ceramic grades
  • Lightweight — 2.7 g/cm³ (0.0975 lb/in³), better than 79% of ceramic grades

Limitations

  • Low stiffness — 100 GPa (14.5 Msi), worse than 75% of ceramic grades

Silicon Carbide NBSC properties

Typical room-temperature values for Silicon Carbide NBSC — 12 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 NBSC has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 79% of ceramic grades. It melts at 2,730°C (4,946 °F).

Density2.7 g/cm³0.1 lb/in³
Melting Point (Solidus)2,730°C4,946 °F
Refractive Index2.65
Porosity13%

Mechanical11

Silicon Carbide NBSC has a tensile strength of 250 MPa (36.3 ksi), stronger than 63% of ceramic grades. The elastic modulus is 100 GPa (14.5 Msi).

Elastic (Young's) Modulus100 GPa14.5 Msi
Shear Modulus175 GPa25.4 Msi
Bulk Modulus220 GPa31.9 Msi
Poisson's Ratio0.16
Tensile Strength (Ultimate)250 MPa36.3 ksi
Compressive Strength250 MPa36.3 ksi
Flexural Strength40 MPa5.8 ksi
Fracture Toughness (K_IC)3.5 MPa·√m3.2 ksi·√in
Hardness, Vickers2,500 HV
Hardness, Knoop2,600 HK
Hardness, Mohs9.3

Thermal5

Silicon Carbide NBSC is rated for continuous service to 1,500°C (2,732 °F). It conducts heat at 16 W/m·K (9.24 BTU/hr·ft·°F), worse than 55% of ceramic grades. Thermal expansion is 4.5 µm/m·K (2.5 µin/in·°F).

Thermal Conductivity16 W/m·K9.2 BTU/hr·ft·°F
Specific Heat Capacity700 J/kg·K0.17 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)4.5 µm/m·K2.5 µin/in·°F
Max Service Temperature (continuous)1,500°C2,732 °F
Min Service Temperature-200°C-328 °F

Electrical2

Silicon Carbide NBSC has an electrical resistivity of 10 Ω·m.

Electrical Resistivity10 Ω·m3.94×10⁸ µΩ·in
Volume Resistivity1,000,000 Ω·cm

Chemical & Environmental2

Corrosion resistance is very good (70/100), worse than 60% of ceramic grades.

Corrosion ResistanceVery good70/100
Chemical Resistance SummaryEssentially inert to acids (including HCl, H2SO4, HNO3, aqua regia) and to most organic media; attacked by hot strong alkalis, molten salts/alkali carbonates and by HF+HNO3 mixtures on the free-silicon or oxide phases; oxidises slowly in air above ~1500 °C forming a protective SiO2 film.

Sustainability4

Producing a kilogram of Silicon Carbide NBSC takes about 80 MJ of energy and emits 5.5 kg of CO₂ — less than 66% of ceramic grades. Typical recycled content is 2%.

Embodied Energy (primary production)80 MJ/kg34,394 BTU/lb
Embodied Carbon (primary production)5.5 kg CO₂/kg
Embodied Water300 L/kg35.9 gal/lb
Typical Recycled Content2%

Manufacturability3

Silicon Carbide NBSC's machinability is poor (15/100, better than 83% of ceramic grades).

MachinabilityPoor15/100
PolishabilityExcellent92/100
Sintering / Firing Temperature1,450°C2,642 °F

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.

Working with Silicon Carbide NBSC

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.

ElementSpec limit (wt %)Nominal
SiCα-SiC (mainly 6H) matrix in the sintered grade98 – 99.899
C (free carbon)sintering aid residue with boron0.1 – 10.5
BB4C/B sintering aid (some grades use Al2O3+Y2O3 instead)0.2 – 10.5
Si (free silicon)sintered grade; 8–15 % in reaction-bonded SiSiC0 – 10.2
Sistoichiometric SiC = 70.05 wt % Si / 29.95 wt % Cbalance

Silicon Carbide NBSC — frequently asked

What is Silicon Carbide NBSC used for?

Silicon Carbide NBSC 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 NBSC?

Silicon Carbide NBSC has a typical tensile strength of 250 MPa (36.3 ksi) — stronger than 63% of ceramic grades. Strength varies by condition: see the 5 listed tempers.

Is Silicon Carbide NBSC easy to machine?

Not especially — machinability is rated poor (15/100, better than 83% 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 NBSC 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 NBSC?

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 NBSC 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 NBSC?

Silicon Carbide NBSC is rated for continuous use to about 1,500°C (2,732 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

Can FabDigit make parts in Silicon Carbide NBSC?

Yes — Silicon Carbide NBSC is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.

Sources

  1. ASM Engineered Materials Handbook, Vol. 4: Ceramics and GlassesASM International (1991)
  2. Hexoloy SA / SE Sintered Silicon Carbide Technical DataSaint-Gobain Ceramics (2023)
  3. Silicon Carbide (SSiC, SiSiC) Material PropertiesCoorsTek (2023)
  4. Fine Ceramics Technical Data — Silicon CarbideKyocera (2022)
  5. GB/T 16552 / GB/T 4740 seriesSAC (China) (2017)
  6. 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.