Silicon Nitride Tubes

Si3N4 tube is a covalent bond compound with high strength, low density, and high temperature resistance.


Silicon Nitride Tubes, Si3N4 Tube


Silicon nitride ceramic is an inorganic material ceramic that does not shrink during sintering. The strength of silicon nitride, especially hot-pressed silicon nitride, is one of the hardest substances in the world. Si3N4 tube is a covalent bond compound with high strength, low density, and high temperature resistance.


Silicon Nitride Tubes Description


Density3.22 g/cm3
Flexural strength800 MPa
Fracture toughness6.5 MPa m^1/2
Thermal stress parameters569 K


Data Sheet & Typical properties of silicon nitride material:


 TypeGas pressure sintered
 Colordark grey
 Water Absorption%0
 Young ModulusGpa290
 Vickers HardnessGpa18 – 20
 Compressive StrengthMpa2200
 Flexural StrengthMpa650
 Thermal ConductivityW/m.K25
 Thermal Shock ResistanceΔ(°C)450 – 650
 Max. Working Temp.°C1200
 Volume ResistivityΩ ·cm> 10^14
 Dielectric Constant8.20
 Dielectric StrengthkV/mm16
* Tests under room temperature environment;

* The above information is offered for comparison only. Exact properties will vary depending on the manufacturing method.


Typical properties of silicon nitride ceramics


-High strength over a wide temperature range

-High fracture toughness

-High hardness

-Outstanding wear resistance

-Low thermal expansion and high thermal conductivity

-Good thermal shock resistance

-Good resistance to chemical and oxidation


Based on the above properties, Silicon Nitride Ceramic is an ideal choice in a wide range of industries, such as:


-Bearing balls and rollers

-Bearing technology in automotive engineering

-Seal Rings

-Valves, turbocharger rotors for engines

-Turbine blades

-Diesel engine glow plugs

-Molten metal handling

-Thermocouple sheaths

-Welding jigs and fixtures

-Welding Rollers


-Centering Pins

-Drawing Tools

-Tube Forming Tools

-High-performance Cutting Tools

-Indexable Inserts

-Tubes and Pipes

-Mechanical Engineering Special Applications


Silicon nitride tubes can also be used as protection for thermocouples. Protection Tubes for Thermocouples made by Si3N4 have excellent corrosion resistance and high-temperature strength and can be used in garbage incinerators and melting furnaces with increased operating temperatures.

A silicon nitride thermocouple protection tube is used to protect the thermocouple that measures the temperature of aluminum and titanium liquid. Features:

-It does not corrode with the aluminum liquid, and the surface does not adhere to the aluminum liquid, which is more conducive to the improvement of the quality of aluminum products;

-Strong oxidation resistance, can be used in the air for a long time below 1000 degrees Celsius, without oxidation;

-100% dense, aluminum liquid cannot be immersed, silicon nitride produced by the reaction sintering process has a short service life, there are many pores in the material, and long-term aluminum liquid will infiltrate;

-Strong thermal shock resistance

-At least the service life in the aluminum industry is 6 months, with actual test is more than 1 year.


Packing of Silicon Nitride Tubes


As a ceramic material, silicon nitride is quite fragile in a lot of cases. Our silicon nitride tubes & silicon nitride protect tubes for thermocouples are carefully handled to minimize damage during storage and transportation. Suitable outer boxes and inner cushioning materials are used for Si3N4 products, vacuum packing is also engaged for some of the parts.


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