Silicon Nitride (Si3N4)

Silicon nitride ceramic has low thermal expansion coefficient, high thermal conductivity and excellent thermal shock resistance. In the very high temperature, silicon nitride keeps a high strength and impact resistance. As an excellent high temperature engineering materials, silicon nitride ceramics are “super hard” providing a high mechanical strength, outstanding wear and very good acid /alkali corrosion resistance. The material is self lubricated.

Applications

  • Low-pressure cast aluminum industry: heating body protection tube, lift tube
  • The photovoltaic industry: long crystal crucible, exhaust hood, heat shield
  • The bearing industry: precision bearings ball, roller
  • Others: mold holder, fusion furnace support, crucible rack, nozzle, insulation ring etc…

Advantages

  • High mechanical strength

Silicon nitride keeps high mechanical strength over a wide temperature range. The outstanding strength characteristics with relative low density make it easy to handle compared to conventional materials.

  • Chemical stability

Silicon nitride is inert against molten metal even at high temperature.  It ensures longer work life with minimum maintenance.

  • Superior thermal shock resistance

Silicon nitride has exceptional high thermal shock resistance – making it ideal for applications with high dynamic stresses, thermal rigor, and demanding reliability requirements

Technical Characteristics – Silicon Nitride (Si3N4)

High purity Si3N4 HS-100 HS-200
Color Grey Black
Porosity ≤0.4 ≤0.4
Density(g/cm3 3.2 3.2
Elastic Modulus(GPa) 320 300
Flexural strength Room(MPa) 780 700
Poisson’s ratio 0.26 0.26
Hardness (Hv) 1800 1500
Thermal expansion(10-6/K) 3.1 3.2
Thermal Conductivity (W/m•K) 20 35
Max. operating temperature Air (℃) 1200 1200
Max. operating temperature Inert Gas (℃) 1500 1500
Thermal shock resistance (K) 600 700
Resistivity(Ω•cm) >1014 >1014
Corrosion resistance Good Good