Boron Nitride Ceramic Threaded Protective Tube
Hot-Pressed Boron Nitride (HPBN), often called “white graphite,” is a high-purity, machinable ceramic sintered from hexagonal boron nitride (hBN). It combines graphite-like lubricity and easy machining with excellent high-temperature stability (up to 2100°C in inert/vacuum), electrical insulation, non-wetting by molten metals, and strong chemical inertness — making it ideal for extreme environments in semiconductors, high-temp melting, and vacuum furnaces.
Material Properties
* High thermal conductivity
* Excellent thermal shock resistance
* Low thermal expansion
* Exceptional heat resistance
* Good Chemical Inertness
* High electrical resistance
* Low dielectric constant and loss tangent
* High volume resistivity
* Excellent machinability
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Boron Nitride Properties:
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Thermal Conductivity
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(40-50)W/m·k
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Thermal expansivity
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(6.5-7.5)*10-6 °C
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Resistivity
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>1012 Ω·m
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Puncture voltage
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(2.5-4.0)*106 /kv·m
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Dielectric constant
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3.8-4.3
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Bending strength
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>35mpa
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Compression strength
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>200mpa
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Density
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1.9—2.2 g/cm3
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Working Temperature
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Oxidizing Atmosphere
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850°C
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Vacuum and inertia
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2000°C
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Applications:
2. Vacuum melting crucibles
3. CVD crucibles
4. Microcircuit packaging
5. Sputtering targets
6. High precision sealing, brazing, and metallizing fixtures
7. Microwave tubes
8. Horizontal caster break rings
9. Low friction seals
10. Plasma arc insulators
11. High temperature furnace fixtures and supports
FAQ
Q1: What is the main advantage of HPBN over alumina or zirconia ceramics?
A: Superior high-temperature stability (2100°C inert), non-wetting by molten metals, and easy machinability — unlike most oxides.
Q2: Can HPBN be machined on regular lathes?
A: Yes — low hardness allows standard carbide tools and tight tolerances (±0.01 mm) without diamond tooling.
Q3: What is the practical temperature limit in air vs. vacuum?
A: Air: ≤900–1000°C long-term. Vacuum/inert: 2000°C+ reliably
