Silicon nitride ceramic material with high thermal stability ,antioxidant ability,and product size excellent performance.
Reaction bonded silicon nitride is made by direct nitridation of a compacted silicon powder, and because of the difficulty of ensuring complete reaction; it is hard to achieve a high component density. Usual densities are in the range 2.3 – 2.5g/cm3 compared with 3.29g/cm3 for gas pressured sintered silicon nitride. The higher density gives the HPSN, SSN & GPS-SSN materials better physical properties and means they are used in more demanding applications at very high temperature, especially for non-ferrous molten metal handling and thermocouple sheaths. The nitridation produces only a small volume change, which means that RBSN components do not need to be machined after fabrication and complex near net shapes can be produced in a single process stage.
Key Properties
Applications exploit the following properties of silicon nitride
low density
high temperature strength
superior thermal shock resistance
excellent wear resistance
good fracture toughness
mechanical fatigue and creep resistance
Excellent non-wetting property with good oxidation resistance
Property | SSN GPS-SSN HPSN RBSN |
Density (g.cm-3) | 3.28 3.30 3.23 2.5 |
Young’s Modulus (GPa) | 285 320 315 189 |
Bend Strength (MPa) | 675 750 850 440 |
Fracture Toughness K1c (MPa.m0.5) | 6 7 8 2.5 |
Hardness (GPa) | 16 16 16 7.2 |
Thermal Expansion Coefficient (x 10-6/°C) | 3.2 3.2 3.2 3.2 |
Thermal Conductivity (W/m.K) | 25 30 30 14 |
Maximum Temperature (°C) for application Dielectric Constant Abrasive Wear resistance Parameter | 1150 1150 1150 1100 9 9 9 7.5 1110 1130 1120 360 |
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Properties mentioned above are for guidance only, ensuring nearest accuracy but may vary in some cases.
