Customized Precision Heat Resistant High Quality Silicon Nitride Ceramic Casing

Overview of Silicon Nitride Ceramic Casing

Silicon Nitride Ceramic Sleeves is a high-performance ceramic product. It is made of silicon nitride as the main raw material through a special process, with high strength, high hardness, high-temperature resistance, wear resistance, oxidation resistance and other excellent characteristics. It can maintain stable performance in harsh environments and can be widely used in metallurgy, chemical industry, electronics and other industries to protect heating elements, thermocouples, etc., and play the role of insulation, protection and prolonged service life.

Features of Silicon Nitride Ceramic Casing

Silicon Nitride Ceramic Sleeves have the following significant features:

High hardness and strength: Silicon Nitride Ceramic Sleeves are extremely hard, second only to diamond and a few other substances. It is able to withstand large external forces without deformation and performs well in machining and abrasion environments, effectively resisting particle scouring and friction to ensure long-term stable use.

Good high-temperature resistance: Silicon nitride ceramic casing has excellent high-temperature resistance and can maintain good mechanical properties and chemical stability in high-temperature environments. It can withstand high temperatures up to 1600℃ and is not easy to soften, deform or melt at high temperatures so that it can work reliably in metallurgy, glass and other high-temperature industrial fields.

Good chemical stability: silicon nitride ceramic casing has excellent corrosion resistance to most acids, alkalis, salts and other chemical substances and is not easily eroded by chemicals; it can be used in chemical, electronic and other industries in contact with corrosive media to ensure that the service life in the harsh chemical environment.

Low coefficient of thermal expansion: the coefficient of thermal expansion of silicon nitride ceramic casing is small when the temperature changes rapidly; the casing is not easy to crack or damage due to thermal stress, has good thermal shock resistance, can adapt to frequent temperature fluctuations, such as in ceramic sintering and other thermal equipment can be operated stably.

Excellent insulation performance: Silicon Nitride ceramics is a good electrical insulator, can effectively isolate the circuit, prevent leakage and short circuits, and can be used in electronics, electric power and other fields of insulation protection to ensure the safe operation of equipment.

Specifications Table of Silicon Nitride Ceramic Casing

Material	Silicon nitride (Si₃N₄)
Color	Black
Size	Typical dimensions include outer diameter 16 – 45mm, inner diameter 8 – 25mm, length 300 – 900mm. Can be customized according to requirements, with diameter range from 0.30 – 50mm and length up to 2000mm46
Accuracy	Dimensional accuracy can reach 0.005mm for diameter, 0.10mm for length, and roundness can be 0.001mm6
Surface roughness	The cylinder surface can be polished to Ra 0.20 or better6
Density	3.1 – 3.3 g/cm³5
Hardness (HV)	1400 – 16002
Bending strength	> 800 MPa2
Compressive strength	> 4000 MPa2
Elastic modulus	300 – 315 GPa2
Fracture toughness	6 – 8 MPa·m¹/²2
Coefficient of thermal expansion	2.2 – 3.0 × 10⁻⁶/℃2
Maximum service temperature	1000℃ in air, 1400℃ in protective atmosphere5
Thermal conductivity	15 – 27 W/(m·K)37
Dielectric strength	20 kV/mm

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Applications of Silicon Nitride Ceramic Casing

Silicon Nitride Ceramic Sleeves have a wide range of applications in many fields due to their excellent performance:

Metallurgical industry: In the continuous casting process, Silicon Nitride Ceramic Sleeves can be used to protect the immersed spout, which can resist the erosion and scouring of molten steel, prolonging the service life of the spout and ensuring the stable pouring of molten steel. Meanwhile, as the protection tube of the heating element in high high-temperature furnace, it can withstand high high-temperature environment, ensure the normal work of the heating element and improve the heating efficiency.

Chemical industry: silicon nitride ceramic casing can be used as a thermocouple protection tube in a variety of corrosive chemical media, can accurately measure the temperature, and is not subject to chemical erosion to ensure the accuracy and stability of temperature measurement. It can also be used for chemical pipeline lining, improve the wear and corrosion resistance of the pipeline, and reduce the maintenance and replacement costs of the pipeline.

Electronics industry: In the semiconductor manufacturing process, silicon nitride ceramic casing used in the ion implantation process can withstand high-energy ion bombardment to protect equipment components from damage. In addition, as an encapsulation material for electronic components, it can provide good insulation and protection to ensure stable performance and reliability of electronic components.

Machining industry: In high-speed cutting processing, silicon nitride ceramic sleeves as the protective sleeve of the tool can improve the wear resistance and thermal stability of the tool, extend the service life of the tool, and improve the machining accuracy and efficiency. Meanwhile, used in abrasives, it can enhance the strength and wear resistance of abrasives and improve the grinding effect.

Company Profile

RBOSCHCO is a trusted global chemical material supplier & manufacturer with over 12 years of experience in providing super high-quality chemicals and Nanomaterials. The company exports to many countries, such as the USA, Canada, Europe, UAE, South Africa, Tanzania, Kenya, Egypt, Nigeria, Cameroon, Uganda, Turkey, Mexico, Azerbaijan, Belgium, Cyprus, Czech Republic, Brazil, Chile, Argentina, Dubai, Japan, Korea, Vietnam, Thailand, Malaysia, Indonesia, Australia, Germany, France, Italy, Portugal etc. As a leading nanotechnology development manufacturer, RBOSCHCO dominates the market. Our professional work team provides perfect solutions to help improve the efficiency of various industries, create value, and easily cope with various challenges. If you are interested, please send an email to sales1@rboschco.com

Payment Term

T/T, Western Union, Paypal, Credit Card etc.

Shipment Term

By air, by sea, by express, as customers request.

5 FAQs of Silicon Nitride Ceramic Casing

Q1:What are the advantages of silicon nitride ceramic casing over alumina ceramic casing?

Silicon nitride ceramics have a higher hardness (about 9 on the Mohs hardness scale, second only to diamond), and wear resistance is more than 3 times that of alumina ceramics. In addition, silicon nitride is more resistant to thermal shock, with a coefficient of thermal expansion that is only 1/3 that of alumina, so it is less likely to crack during sudden temperature changes. In extra-high-voltage electrical equipment, the volume of silicon nitride ceramic pillar insulators is 50% less than that of conventional alumina components, and the insulation strength is increased by 30%.

Q2:What is the self-lubricating performance of silicon nitride ceramic bushings?

Silicon nitride ceramic will generate a nano-sized SiO₂ lubrication film on the surface during the friction process, and the dry friction coefficient is as low as 0.1-0.3, which is especially outstanding in high temperature (above 300℃) or non-lubricated environment.

Q3:Q Can silicon nitride ceramic casing withstand strong corrosive environment?

Silicon nitride has excellent corrosion resistance to strong acids, bases and molten salts other than hydrofluoric acid. In an aluminum electrolyzer, it can resist erosion by cryolite molten salt at 960°C for 18 months of continuous service without significant corrosion. In the saltwater environment containing H₂S, the annual corrosion rate is only 0.002mm, much lower than stainless steel.

Q4: How to solve the brittleness problem of silicon nitride ceramic casing?

Through rare earth doping (e.g., Er₂O₃) and grain boundary engineering, the melting point of the glass phase at the grain boundary can be raised from 1450°C to 1650°C, significantly enhancing toughness. In practice, the use of a “beer-bottle” shape design reduces stress concentrations, resulting in a 50% increase in mechanical strength.

Q5:Is the manufacturing process of silicon nitride ceramic casing complex?

The preparation of silicon nitride ceramic sleeves involves nitriding, molding, and sintering of high-purity silicon powder. Reaction sintering is suitable for complex shapes, while gas pressure sintering (GPS) can produce highly dense products with densities close to theoretical values. Precision machining requires the use of diamond grinding wheels, and the precision of mirror surface machining can reach Ra <0.05μm.