Silicon nitride (Si₃N₄), aluminium oxide (Al₂O₃), and aluminium titanate (Al₂TiO₅). These three materials all fall within the category of advanced ceramics or engineering ceramics, featuring high melting points, high hardness, excellent chemical stability, good wear resistance and certain high-temperature resistance. However, their core characteristics are significantly different:
Silicon nitride(Si₃N₄): Renowned for its high strength, high toughness, excellent thermal shock resistance and good high-temperature strength retention rate, it is a representative of high-performance structural ceramics.
Alumina(Al₂O₃): It is known for its high hardness, excellent wear resistance, good electrical insulation, chemical inertness and relatively low cost, and is the most widely used engineering ceramic.
Aluminum titanate(Al₂TiO₅): Its most prominent feature is an extremely low coefficient of thermal expansion, which brings excellent thermal shock resistance. However, its mechanical strength is relatively low, and there is a problem of thermal decomposition within a certain temperature range.
Typical application fields
Silicon nitride (Si₃N₄):
High-temperature structural components: Gas turbine parts (turbine rotor blades, burner bushings), diesel engine parts (electric heating plugs, turbocharger rotors), high-temperature bearings, kiln furniture (rollers, brackets).
Wear-resistant parts: cutting tools, sealing rings, pump components, rolls, bearing balls.
Thermal shock-resistant components: Metal melt treated components (immersion thermocouple sleeves, riser tubes), heat exchanger components.
Others: Semiconductor manufacturing equipment components (fixtures, heater bases), bioceramics (artificial joints).
Aluminum oxide (Al₂O₃)
Electrical insulators: Electronic substrates (IC packaging, thick and thin film circuit substrates), spark plug insulators, high-voltage insulators, vacuum tube/microwave tube components.
Wear-resistant parts: sealing rings, plunger pump components, bearings (especially mixed ceramic bearing ball sleeves), textile wire guides, nozzles, grinding media (balls, linings).
Corrosion-resistant parts: Chemical pumps, valve components, laboratory vessels (crucibles, tubes).
Biomedical: Artificial joints (hip, knee), dental implants (implant abutments).
High-temperature components: refractory materials, kiln linings, thermocouple sleeves (thermal shock needs to be considered).
Others: Abrasives, cutting tools (metal cutting), laser tubes, transparent armor (transparent alumina).
Aluminum titanate (Al₂TiO₅):
Key components for thermal shock resistance: Automotive engine parts (exhaust pipe lining, thermal barrier coating base material, piston top insert), metal melt treatment parts (protective sleeve, crucible, pouring cup), high-temperature furnace lining/kiln furniture (support, roller rod), heat exchanger parts.
Low thermal expansion components: Precision instrument components that require dimensional stability (in environments with temperature fluctuations).
Thermal insulation component: Utilizing its low thermal conductivity.
Filtration and catalytic carriers: Porous structures are used for the filtration of molten metals or as catalyst carriers (taking advantage of their chemical stability and specific pore structure).
