Introduction of Silicon nitride pressure sintering furnace
A Silicon Nitride Pressure Sintering Furnace is a high-end thermal processing system specifically designed for the densification of high-performance silicon nitride (Si₃N₄) ceramics. Due to its strong covalent bonding structure, silicon nitride cannot achieve high density through conventional pressureless sintering and requires specialized techniques such as high-temperature gas pressure sintering (GPS) under high-purity nitrogen atmosphere or hot isostatic pressing (HIP). Among these, the gas pressure sintering furnace (GPS furnace) has become the industry standard, as it offers an optimal balance of performance, cost-effectiveness, and the ability to fabricate complex-shaped components.It is available in both horizontal and vertical configurations.
Working principle of Silicon nitride pressure sintering furnace
Silicon nitride pressure sintering furnaces typically employ the Gas Pressure Sintering (GPS) process:
Loading: Si₃N₄ green compacts, doped with sintering aids (e.g., Y₂O₃–Al₂O₃, MgO, etc.), are placed into graphite or boron nitride (BN) crucibles.
Vacuum Degassing: Air and moisture are evacuated to prevent oxidation.
Heating and Pressurization: The furnace is heated to 1700–1900°C while high-purity nitrogen gas (N₂ ≥ 99.999%) at 5–10 MPa is introduced to suppress high-temperature decomposition of Si₃N₄ (Si₃N₄ → Si(l) + N₂↑).
Soaking under Pressure: The material is held at high temperature and pressure for several hours to facilitate liquid-phase sintering and full densification.
Controlled Cooling: The furnace is slowly cooled under a nitrogen atmosphere to prevent thermal stress-induced cracking.
Application of Silicon nitride pressure sintering furnace
Silicon nitride ceramic balls, bearings, thermal conductive substrates, stages/platforms, linear guideways, cutting tools, structural components, etc.
Technical Feature of Silicon nitride pressure sintering furnace
Special crucible (muffle) design and optimized heater arrangement ensure excellent temperature uniformity.
Fully sealed muffle chamber provides superior sealing performance and strong resistance to contamination.
Capable of multiple sintering modes: vacuum sintering, pressure sintering, negative-pressure debinding sintering, and slight positive-pressure sintering.
Equipped with comprehensive safety features including over-temperature and over-pressure alarms, mechanical automatic pressure relief, and interlocked operational sequences for high equipment safety.
Optional integrated debinding system available for one-step debinding and sintering of ceramic components.
Compatible with various process atmospheres: N₂ / Ar / H₂.
