Silicon nitride ceramic tube

Silicon Nitride Ceramic Tube Product Introduction:

Silicon nitride (Si₃N₄) ceramic is a high-performance ceramic material bonded by strong covalent bonds. Its microstructure typically consists of interwoven, elongated β-Si₃N₄ grains, giving the material extremely high intrinsic strength and toughness. Key characteristics include:

1. Physical Properties: Extremely low thermal expansion coefficient (approximately 3.2 × 10⁻⁶/℃) and high thermal conductivity (approximately 20-30 W/m·K), exhibiting superior thermal shock resistance; high hardness (second only to silicon carbide and cubic boron nitride), good wear resistance, and high fracture toughness.

2. Chemical Properties: Excellent stability at high temperatures, resistant to corrosion from most acids and bases (except hydrofluoric acid and concentrated strong bases), with an oxidation resistance temperature exceeding 1400℃.

3. Mechanical Properties: Bending strength can reach 600-8200 MPa, and Mohs hardness is as high as 8-9.

Application Fields

Silicon nitride ceramic tubes have wide applications in several high-end fields:

1. Aerospace: Used in components requiring high temperature resistance and oxidation resistance, such as aircraft engine blades.

2. Energy and Power: Used in superheaters of supercritical coal-fired power plants, with a lifespan exceeding 10 years (compared to only 2-3 years for metal tubes); and in helium heat exchanger tubes for high-temperature gas-cooled reactors in the nuclear energy field, meeting a 60-year service life requirement.

3. Industrial Manufacturing: Used in high-temperature molten metal equipment such as aluminum electrolytic cells and continuous casting of copper alloys; enabling continuous casting speed to increase from 1.2 m/min to 2.5 m/min, and reducing energy consumption by 40%.

4. Environmental Protection Technology: Used in core environmental protection fields such as exhaust gas treatment, wastewater treatment, and industrial filtration.