Silicon Nitride Tube Description
Silicon nitride is an advanced ceramic material with a high melting point. It has extremely high hardness and excellent wear resistance, and can maintain a stable structure even in harsh working environments.
GORGEOUS can customize silicon nitride ceramic tubes for customers. Regardless of the size, shape or performance requirements under special working conditions, we can combine our rich manufacturing experience and advanced technology to create durable, efficient and stable silicon carbide ceramic tubes for you to meet the needs of various metallurgical, chemical and heat treatment equipment.
Silicon Nitride Ceramic Tube Specifications
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Silicon Nitride Mechanical Properties |
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كثافة |
3.2 g/cm3 |
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قوة الانحناء |
900 MPa |
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قوة الضغط |
3000 MPa |
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Weibull-Modulus m |
15 |
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Fracture Toughness KIc |
6.0 MPa m1/2 |
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Young’s Modulus E |
320 GPa |
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Poisson Ratio |
0.28 |
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Hardness Vickers (HV 1) |
16 GPa |
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Silicon Nitride Thermal properties |
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Maximum operating temperature(Inert gas) |
1200درجة مئوية |
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Maximum operating temperature(Air) |
1100درجة مئوية |
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Thermal conductivity at 20°C |
28 W/mK |
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Thermal conductivity at 1000°C |
16 W/mK |
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Thermal Expansion (20–100°C) |
2*10-6/ك |
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Thermal Expansion (20–1000°C) |
3.5*10-6/ك |
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Electrical properties of silicon nitride |
|
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Electrical properties |
1012 Ωcm |
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Resistivity at 800°C |
107 Ωcm |
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ثابت العزل الكهربائي |
6 MHz |
Application
Silicon nitride tubes are used as follows：
- أنبوب حماية حراري
- Molten metal processing equipment
- High temperature furnace tube and heating element protection
- Precision mechanical parts and wear-resistant guide parts
- Chemical equipment and fluid delivery system
Silicon Nitride Ceramic Tube Manufacturing Process
GORGEOUS can customize different grades of silicon nitride ceramic tubes according to customer needs.
Gas overpressure sintering silicon nitride
This process uses gas overpressure sintering technology to produce silicon nitride parts with complex shapes and high strength requirements.
The main process flow includes: mixing silicon nitride powder with sintering additives (such as yttrium oxide, magnesium oxide or aluminum oxide), increasing density through liquid phase sintering, and adding binders to enhance the structural integrity of the pre-sintered body.
After the powder is formed and green processed, it is sintered and densified in a pressurized nitrogen atmosphere, effectively reducing the loss caused by element evaporation or decomposition, thereby obtaining high-strength and high-density ceramic products.
Hot-pressing sintering silicon nitride
The hot-pressing sintering process is to heat and uniaxially press the silicon nitride powder at high temperature and pressure.
This process can produce ceramic materials with high density and excellent strength, which are suitable for applications with high performance requirements. However, due to equipment limitations, it is only suitable for producing parts with relatively simple geometric shapes; and the formed parts cannot be processed in the green state. All complex processing needs to be completed by diamond grinding after sintering. The process is complicated and the cost is high, so it is usually used for small-batch production of high-performance parts.
Hot isostatic pressing (HIP) silicon nitride
This process uses hot isostatic pressing to place silicon nitride powder under high temperature (about 1700–1800°C) and high pressure (up to 2000 bar) in an inert gas environment and sinter simultaneously.
The residual porosity in the sintered body is significantly reduced by uniform pressure in all directions, and a material close to the theoretical density is obtained. This method greatly improves the mechanical strength, durability and overall reliability of the material, but due to the complex process and high cost, it is mostly used in key components and special industrial fields that require extremely high performance.
Extrusion gas overpressure sintering of silicon nitride
Based on the traditional gas overpressure sintering, combined with extrusion molding technology, silicon nitride powder is first mixed with sintering aids (such as yttrium oxide, magnesium oxide, aluminum oxide, etc.), and a binder is added to improve the mechanical properties of the green body.
After the material is made into a specific shape by extrusion, it enters a controlled environment for gas overpressure sintering. This process can achieve ceramic products with more uniform structure and higher density, which is especially suitable for the production needs of high-performance and complex structural components.
