Silicon Nitride SRBSN
Grade
also Sintered Silicon Nitride
SRBSN = sintered reaction-bonded silicon nitride
Route that starts from cheap Si powder and then densifies; gives near-SSN properties with less shrinkage and lower raw-material cost for larger parts.
Values for the SRBSN condition
Other Silicon Nitride tempers and conditions
Silicon Nitride is listed in 6 conditions; see the grade overview at Silicon Nitride.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Reaction-bonded silicon nitride | Low-cost, near-zero-shrinkage porous grade for large refractory shapes, thermocouple sheaths, riser tubes and molten-aluminium hardware where strength is secondary. | 160 | 900 HV | 12 W/m·K | ||
SRBSNThis page Sintered reaction-bonded silicon nitride | Route that starts from cheap Si powder and then densifies; gives near-SSN properties with less shrinkage and lower raw-material cost for larger parts. | 400 | 0 | 1,450 HV | 40 W/m·K | |
SinteredDefault pressureless / gas-pressure sintered Si3N4 (SSN) | Standard dense grade for general structural, wear and high-temperature parts; best cost/performance for complex near-net shapes. | 450 | 1,500 HV | 25 W/m·K | ||
Hot isostatic pressed | Pick when defect-free, fully dense material is required — bearing balls/rollers, high-cycle-fatigue and highly stressed parts. | 550 | 1,600 HV | 30 W/m·K | ||
Uniaxially hot-pressed Si3N4 | Choose for the highest strength in simple plate/blank geometries (cutting inserts, tooling); shapes limited and properties slightly anisotropic. | 550 | 0 | 1,650 HV | 30 W/m·K | |
High-thermal-conductivity Si3N4 substrate grade | Y2O3-based, low-oxygen, coarse-β-grain grade for AMB power-module substrates: 70–100 W/m·K with substrate-grade strength and toughness. | 1,450 HV | 90 W/m·K |
What is Silicon Nitride SRBSN?
Silicon Nitride SRBSN is Silicon Nitride in the SRBSN grade — route that starts from cheap Si powder and then densifies; gives near-SSN properties with less shrinkage and lower raw-material cost for larger parts. Silicon Nitride SRBSN has a tensile strength of 400 MPa (58 ksi), stronger than 74% of ceramic grades. Elongation at break is 0% and the elastic modulus is 300 GPa (43.5 Msi). Silicon Nitride SRBSN has a density of 3.2 g/cm³ (0.116 lb/in³), lighter than 72% of ceramic grades. It melts at 1,900°C (3,452 °F). Sintered is the default condition FabDigit quotes; SRBSN is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 92/100, better than 89% of ceramic grades
- Good corrosion resistance — 89/100, better than 79% of ceramic grades
- High service temperature — 1,250°C (2,282 °F), better than 76% of ceramic grades
Silicon Nitride SRBSN properties
Typical room-temperature values for Silicon Nitride SRBSN; 15 are specific to this condition. Other listed values are Silicon Nitride reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical4
Silicon Nitride SRBSN has a density of 3.2 g/cm³ (0.116 lb/in³), lighter than 72% of ceramic grades. It melts at 1,900°C (3,452 °F).
Mechanical12
Silicon Nitride SRBSN has a tensile strength of 400 MPa (58 ksi), stronger than 74% of ceramic grades. Elongation at break is 0% and the elastic modulus is 300 GPa (43.5 Msi).
Thermal5
Silicon Nitride SRBSN is rated for continuous service to 1,250°C (2,282 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), better than 67% of ceramic grades. Thermal expansion is 3.2 µm/m·K (1.78 µin/in·°F).
Electrical5
Silicon Nitride SRBSN is an electrical insulator with a dielectric strength of 15 kV/mm (381 V/mil) and a resistivity of 1×10¹¹ Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (89/100), better than 79% of ceramic grades.
Sustainability4
Producing a kilogram of Silicon Nitride SRBSN takes about 170 MJ of energy and emits 12 kg of CO₂ — more than 59% of ceramic grades. Typical recycled content is 0%.
Manufacturability3
Silicon Nitride SRBSN's machinability is not recommended (6/100, better than 61% of ceramic grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Silicon Nitride SRBSN
Is Silicon Nitride easy to machine?
Green/bisque machining with carbide tooling is the economical route; after sintering only diamond grinding, lapping and laser/ultrasonic machining work (electrically insulating, so no EDM).
Can Silicon Nitride be welded?
Not weldable — join by active-metal brazing (Ti-containing Ag-Cu), metallization + soldering, glass sealing or mechanical shrink-fit; AMB copper bonding is standard for substrates.
Can Silicon Nitride be formed, bent or molded?
Formed as a powder compact: uniaxial/isostatic pressing, injection moulding, slip/tape casting or extrusion, then sintered at 1650–1850 °C under N2 overpressure with ~15–18 % linear shrinkage (RBSN routes are near net shape).
What surface finishes work on Silicon Nitride?
Diamond lapping and polishing give Ra < 0.01 µm on bearing surfaces; CVD/PVD coatings, metallization or lapped-and-honed seal faces are common — no anodizing/plating without prior metallization.
Silicon Nitride 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 |
|---|---|---|
| Y2O3primary sintering aid (rare-earth oxide; may be substituted by Yb2O3/La2O3) | 0 – 8 | 4 |
| Al2O3co-additive; forms grain-boundary glass, lowers thermal conductivity | 0 – 5 | 2 |
| MgOalternative aid, mainly in hot-pressed grades | 0 – 3 | 0 |
| SiO2surface oxide on powder, part of the glass phase | 0.5 – 2.5 | 1.2 |
| Feimpurity | 0 – 0.2 | 0.05 |
| Si3N4predominantly β-Si3N4 after sintering | ≥ 88 (balance) |
Silicon Nitride SRBSN — frequently asked
What is Silicon Nitride SRBSN used for?
Silicon Nitride SRBSN is typically used for hybrid bearing balls and rollers, hot rolling bearings, turbocharger rotors, diesel glow plugs, cutting tool inserts for cast iron and welding locator pins and molten aluminum riser tubes. In short: high-toughness silicon nitride.
What is the tensile strength of Silicon Nitride SRBSN?
Silicon Nitride SRBSN has a typical tensile strength of 400 MPa (58 ksi) — stronger than 74% of ceramic grades. Strength varies by condition: see the 6 listed tempers.
Is Silicon Nitride SRBSN easy to machine?
Not especially — machinability is rated not recommended (6/100, better than 61% of ceramic grades). Green/bisque machining with carbide tooling is the economical route; after sintering only diamond grinding, lapping and laser/ultrasonic machining work (electrically insulating, so no EDM).
Can Silicon Nitride SRBSN be welded?
Not weldable — join by active-metal brazing (Ti-containing Ag-Cu), metallization + soldering, glass sealing or mechanical shrink-fit; AMB copper bonding is standard for substrates.
What surface finishes work on Silicon Nitride SRBSN?
Diamond lapping and polishing give Ra < 0.01 µm on bearing surfaces; CVD/PVD coatings, metallization or lapped-and-honed seal faces are common — no anodizing/plating without prior metallization.
Can Silicon Nitride SRBSN be formed, bent or molded?
Formed as a powder compact: uniaxial/isostatic pressing, injection moulding, slip/tape casting or extrusion, then sintered at 1650–1850 °C under N2 overpressure with ~15–18 % linear shrinkage (RBSN routes are near net shape).
What is the maximum service temperature of Silicon Nitride SRBSN?
Silicon Nitride SRBSN is rated for continuous use to about 1,250°C (2,282 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASM Engineered Materials Handbook, Vol. 4: Ceramics and Glasses — ASM International (1991)
- ISO 26602 — Fine ceramics: Silicon nitride materials for rolling bearing balls and rollers — ISO (2017)
- ASTM C1161 / C1421 — Flexural strength and fracture toughness of advanced ceramics — ASTM (2018)
- Silicon Nitride (Si3N4) material property sheets — CoorsTek (2023)
- Fine Ceramics — Silicon Nitride SN series — Kyocera (2023)
- SL200B / high-thermal-conductivity Si3N4 substrate data — CeramTec / Rogers curamik (2022)
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.