Sialon BETA
Grade · default condition
BETA = β-Sialon
Default structural grade: best balance of strength, toughness and thermal shock for thermocouple sheaths, weld pins, riser tubes and pump parts.
Values for the BETA condition
Other Sialon tempers and conditions
Sialon is listed in 3 conditions; see the grade overview at Sialon.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
General-purpose sintered sialon | Lower-cost, slightly less dense grade for wear plates, nozzles and molten-metal handling where peak strength is not required. | — | — | — | 1,350 HV | 16 W/m·K |
BETADefaultThis page Β-Sialon | Default structural grade: best balance of strength, toughness and thermal shock for thermocouple sheaths, weld pins, riser tubes and pump parts. | — | — | — | 1,550 HV | 21 W/m·K |
As built (as printed) | Pick when hardness and hot wear resistance dominate — inserts for turning/milling nickel superalloys and grey cast iron at high speed. | — | — | — | 1,800 HV | 20 W/m·K |
What is Sialon BETA?
Sialon BETA is Sialon in the BETA grade — default structural grade: best balance of strength, toughness and thermal shock for thermocouple sheaths, weld pins, riser tubes and pump parts. Sialon BETA has a tensile strength of 350 MPa (50.8 ksi), stronger than 71% of ceramic grades. The elastic modulus is 288 GPa (41.8 Msi). Sialon BETA has a density of 3.25 g/cm³ (0.117 lb/in³), lighter than 70% of ceramic grades. It melts at 1,800°C (3,272 °F).
Advantages
- Good corrosion resistance — 90/100, better than 81% of ceramic grades
- Tough — resists crack growth — 7.7 MPa·√m (7.01 ksi·√in), better than 76% of ceramic grades
Sialon BETA properties
Typical room-temperature values for Sialon BETA; 11 are specific to this condition. Other listed values are Sialon reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical3
Sialon BETA has a density of 3.25 g/cm³ (0.117 lb/in³), lighter than 70% of ceramic grades. It melts at 1,800°C (3,272 °F).
Mechanical11
Sialon BETA has a tensile strength of 350 MPa (50.8 ksi), stronger than 71% of ceramic grades. The elastic modulus is 288 GPa (41.8 Msi).
Thermal5
Sialon BETA is rated for continuous service to 1,200°C (2,192 °F). It conducts heat at 21 W/m·K (12.1 BTU/hr·ft·°F), worse than 52% of ceramic grades. Thermal expansion is 3 µm/m·K (1.67 µin/in·°F).
Electrical5
Sialon BETA 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 (90/100), better than 81% of ceramic grades.
Sustainability4
Producing a kilogram of Sialon BETA takes about 230 MJ of energy and emits 14 kg of CO₂ — more than 65% of ceramic grades. Typical recycled content is 0%.
Manufacturability3
Sialon BETA's machinability is not recommended (4/100, worse than 85% of ceramic grades).
Common Calculations4
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Sialon BETA
Is Sialon easy to machine?
Green/bisque machining is preferred; after sintering only diamond grinding, lapping or (TiN grade) EDM works — allow ~20 % shrinkage in green design.
Can Sialon be welded?
Not weldable; joined by active-metal brazing (Ti-containing AgCu filler), glass sealing or mechanical shrink/clamp mounts with compliant gaskets.
Can Sialon be formed, bent or molded?
Formed by uniaxial/cold-isostatic pressing, slip or injection moulding of Si3N4+AlN+Al2O3+Y2O3 powder, then pressureless or gas-pressure sintering at 1650–1850 °C in N₂; HIP for maximum density.
What surface finishes work on Sialon?
Diamond lapping/polishing to Ra < 0.05 µm; edges must be honed or chamfered to avoid chipping; CVD/PVD coatings (TiN, Al₂O₃) applied on cutting-tool grades.
Sialon 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 |
|---|---|---|
| Sias β-Si6-zAlzOzN8-z, z ≈ 0.5–1.5 for engineering grades | 42 – 58 | 50 |
| N | 27 – 36 | 34 |
| Alsubstitutes for Si in the lattice | 3 – 14 | 9.5 |
| Olattice O plus grain-boundary glass | 2 – 9 | 5.5 |
| Y (as Y2O3 sintering aid)some grades use Yb2O3/Ce2O3 or MgO instead | 0.5 – 5 | 2.5 |
| Si+Al+O+N balanceimpurities (Fe, Ca) typically < 0.5 % | balance | — |
Sialon BETA — frequently asked
What is Sialon BETA used for?
Sialon BETA is typically used for cutting inserts for nickel alloys, molten metal handling, thermocouple protection tubes and wear parts. In short: superalloy-turning insert ceramic; best thermal-shock nitride; EDM-capable TiN grade.
What is the tensile strength of Sialon BETA?
Sialon BETA has a typical tensile strength of 350 MPa (50.8 ksi) — stronger than 71% of ceramic grades. Strength varies by condition: see the 3 listed tempers.
Is Sialon BETA easy to machine?
Not especially — machinability is rated not recommended (4/100, worse than 85% of ceramic grades). Green/bisque machining is preferred; after sintering only diamond grinding, lapping or (TiN grade) EDM works — allow ~20 % shrinkage in green design.
Can Sialon BETA be welded?
Not weldable; joined by active-metal brazing (Ti-containing AgCu filler), glass sealing or mechanical shrink/clamp mounts with compliant gaskets.
What surface finishes work on Sialon BETA?
Diamond lapping/polishing to Ra < 0.05 µm; edges must be honed or chamfered to avoid chipping; CVD/PVD coatings (TiN, Al₂O₃) applied on cutting-tool grades.
Can Sialon BETA be formed, bent or molded?
Formed by uniaxial/cold-isostatic pressing, slip or injection moulding of Si3N4+AlN+Al2O3+Y2O3 powder, then pressureless or gas-pressure sintering at 1650–1850 °C in N₂; HIP for maximum density.
What is the maximum service temperature of Sialon BETA?
Sialon BETA is rated for continuous use to about 1,200°C (2,192 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ISO 26845 — Chemical analysis of refractories, general requirements — ISO (2008)
- ASM Engineered Materials Handbook, Vol. 4: Ceramics and Glasses — ASM International (1991)
- Syalon 050 / 101 / 110 / 501 technical datasheets — International Syalon (2023)
- Silicon nitride & sialon cutting tool material data — Kyocera / CoorsTek (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.