Silicon nitride has better thermal shock resistance than other ceramics. Combined with high strength, low thermal expansion, good corrosion resistance and fracture toughness, silicon nitride is often used in the aerospace or automotive industries. Other applications such as burner nozzles, molten metal processing, etc. Electrical insulation, good corrosion resistance, medium operating temperature (13000C), structural ceramics, good mechanical properties, low thermal expansion, high thermal conductivity, very good thermal shock stability, low specific gravity.
Silicon nitride is a gray ceramic with high fracture toughness, excellent heat shock resistance, and relatively impenetrable properties to molten metals.
Using these characteristics, it is applied to internal combustion engine parts such as automobile engine parts, welding machine blowpipe nozzles, etc., especially parts that need to be used in harsh environments such as overheating.
With its high wear resistance and high mechanical strength, its applications in bearing roller parts, rotating shaft bearings and semiconductor production equipment spare parts are constantly expanding.
Propriétés de la céramique au nitrure de silicium
1, a une forte résistance dans une grande plage de températures;
2, force de fracture élevée;
3, bonne force de flexion;
4, résistance à la fatigue mécanique et au fluage;
5, lumière - basse densité;
6, résistance élevée à la dureté et à l'usure;
7, excellente résistance aux chocs thermiques;
8, faible dilatation thermique;
9, isolant électrique;
10, bonne résistance à l'oxydation;
11, bonne résistance à la corrosion chimique.
Silicon nitride ceramics have low thermal expansion coefficient and high thermal conductivity, so they have excellent heat shock resistance. The hot-pressed sintered silicon nitride will not break after being heated to 1000℃ and put into cold water. At not too high a temperature, silicon nitride has a high strength and impact resistance, but above 1200℃ will be damaged with the growth of use time, so that its strength is reduced, more prone to fatigue damage above 1450℃, so the use of Si3N4 temperature generally does not exceed 1300℃.
Therefore, silicon nitride has been widely used in:
1. Rotating ball and roller bearings;
2. Engine components: valve, rocker arm pad, sealing surface;
3. Induction heating coil bracket;
4. Turbine blades, blades, buckets;
5. Welding and brazing fixtures;
6. Heating element assembly;
7. Welding positioner;
8. Precision shafts and sleeves in high-wear environments;
9. Thermocouple sheath and tube;
10. Semiconductor process equipment.
