Silicon Nitride (Si₃N₄) ceramics, particularly Gas Pressure Sintered (GPS) grades, are high-performance technical ceramics engineered for extreme mechanical, thermal and corrosive environments.

Manufactured from high-purity α-phase Si₃N₄ powder (>90%) with sintering aids (Y₂O₃–Al₂O₃), the material is formed by dry pressing or cold isostatic pressing (CIP), then sintered under nitrogen gas pressure. This process promotes β-Si₃N₄ whisker growth and achieves full densification.

Key strengths include high density (3.20–3.26 g/cm³), very low porosity (0–0.2 %), outstanding flexural strength (700–900 MPa), excellent fracture toughness and superior thermal shock resistance.

A defining advantage for the aluminum casting industry is the non-wetting and non-reactive behavior toward molten aluminum — molten aluminum does not adhere to the surface, significantly reducing aluminum loss, build-up and clogging while providing excellent corrosion resistance against molten aluminum and certain molten salts.

We also supply porous silicon nitride-bonded silicon carbide (Si₃N₄-SiC) filter materials with interconnected open pores for molten metal filtration.

Material Grades & Variants

Source-recorded material routes and typical reference values support preliminary selection. Final specifications are confirmed against grade, drawing, operating conditions and test basis.

Grade / Variant	Composition / Type	Key Characteristics	Typical Applications
Gas Pressure Sintered Silicon Nitride (GPS Si₃N₄) — primary high-performance dense grade	Gas Pressure Sintered Silicon Nitride (GPS Si₃N₄) — primary high-performance dense grade	Source-recorded material route; supplier-specific values require verification.	Application-dependent
Reaction-Bonded / other sintered Si₃N₄ variants	Reaction-Bonded / other sintered Si₃N₄ variants	Source-recorded material route; supplier-specific values require verification.	Application-dependent
Silicon Nitride-bonded Silicon Carbide (Si₃N₄-SiC) porous grades for filtration	Silicon Nitride-bonded Silicon Carbide (Si₃N₄-SiC) porous grades for filtration	Source-recorded material route; supplier-specific values require verification.	Application-dependent

Typical reference values for material selection only. Final specifications are confirmed against drawing, grade and operating conditions.

Silicon Nitride Degassing Rotors

Silicon Nitride Degassing Rotors are core purification components used in aluminum melting and casting processes.

View product

Silicon Nitride Heater Protection Tubes

Silicon Nitride Heater Protection Tubes are high-performance ceramic sleeves designed to protect electric heating elements (resistance wires, SiC rods, MoSi₂ rods, etc.) from high temperature, corrosion, oxidation and mechanical damage in harsh industrial environments.

View product

Silicon Nitride Plates

Silicon Nitride Plates are high-performance fully dense ceramic plates manufactured by isostatic pressing and high-temperature sintering.

View product

Silicon Nitride Positioning Pins / Ceramic Dowel Pins for Projection Welding

Silicon Nitride Positioning Pins (also known as ceramic dowel pins or locating pins) are precision components designed for accurate positioning of weld nuts and studs in projection welding and resistance welding fixtures.

View product