Application of silicon nitride ceramics in the preparation of fine ceramics

---

Silicon nitride ceramics, as an advanced structural ceramic material, occupy a core position in the field of modern fine ceramic preparation due to their high strength, high toughness, excellent high temperature resistance, and good thermal shock resistance. It can be made into high-precision components such as bearing balls, cutting tools, turbine rotors, etc. through complex powder preparation, molding, and sintering processes, and is widely used in high-end manufacturing fields such as aerospace, new energy vehicles, and semiconductor equipment.

Product FAQ: We will answer the questions you are concerned about
Q: In the application of high-precision bearings, traditional metal bearings are prone to heating and wear during high-speed operation, and have a short lifespan. Can silicon nitride ceramic bearings solve this problem?
Answer: Absolutely possible. The density of silicon nitride ceramic bearings is only one-third of that of bearing steel, and the centrifugal force is small during operation, allowing for higher rotational speeds; At the same time, its self-lubricating properties reduce frictional heating, and it has excellent high temperature resistance. Its strength and hardness remain almost unchanged at 800 ℃, and its service life can be increased by 3-5 times compared to metal bearings.
Q: In semiconductor manufacturing equipment, materials that are both insulating and resistant to plasma corrosion are needed. Can silicon nitride ceramics meet the requirements?
Answer: Silicon nitride ceramics have excellent electrical insulation properties and plasma corrosion resistance, high volume resistivity, and good chemical stability. They are ideal materials for key components such as semiconductor etching equipment and ion implantation machines, and can effectively solve the corrosion and pollution problems of metal components in harsh process environments.
Q: Do silicon nitride ceramic products support small batch customization and non-standard size processing?
Answer: We provide full process customization services from material formulation to finished product delivery. Whether you need miniature bearing balls with a diameter of 0.5mm, large structural components with a diameter of 500mm or more, or irregular parts with complex inner cavities, through holes, and threads, we can perform precision machining according to your CAD drawings. The dimensional tolerance can be controlled within ± 0.005mm, and the surface roughness Ra can reach 0.2 μ m.

Material characteristics and fine preparation process of silicon nitride ceramics

1. Unique performance advantages of silicon nitride
   Silicon nitride (Si ∝ N ₄) is known as the “king of structural ceramics”, and its performance advantages are reflected in multiple dimensions:
   -Excellent mechanical properties: bending strength can reach over 1000MPa, fracture toughness 6-10 MPa · m ¹/², hardness HRA 90 or above, combining high strength and high toughness, which is very rare in ceramic materials.
   -Outstanding high temperature resistance: It can be used up to 1200-1300 ℃ in air, and can withstand even higher temperatures in an inert atmosphere. It has high high-temperature strength retention and excellent thermal shock resistance. Even when heated to 1000 ℃ and poured into cold water, it does not crack.
   -Excellent physical properties: low density (about 3.2g/cm ³), low coefficient of thermal expansion (about 3.0 × 10 ⁻⁶/℃), high thermal conductivity (20-30 W/m · K), the combination of these characteristics allows it to maintain dimensional stability even under conditions of drastic temperature changes.
   -Good chemical stability: except for hydrofluoric acid, it has good corrosion resistance to all other inorganic acids and alkaline solutions, especially outstanding corrosion resistance to aluminum liquid.
2. Key processes for the preparation of fine ceramics
   The preparation of silicon nitride ceramics is a sophisticated manipulation of the microstructure of the material. The difficulty of its process lies in the fact that silicon nitride is a strong covalent compound, which is extremely difficult to sinter densely and requires complex process design to achieve high performance.
   Powder preparation is the foundation: high-quality silicon nitride powder is the prerequisite for high-performance ceramics. At present, the advanced temperature controlled activated combustion synthesis method can shorten the reaction time from 72 hours in traditional processes to 4 hours, significantly reducing energy consumption and costs, while ensuring high purity and high activity of the powder.
   Forming and sintering are key: by adding oxide additives (such as Y ₂ O3, Al ₂ O3), a liquid phase is formed at high temperatures, promoting densification through a “dissolution precipitation” mechanism. Hot isostatic pressing technology can increase the relative density to over 99.6%, significantly improving the mechanical properties and fatigue life of ceramic balls.
   Precision machining is a guarantee: using specialized high-precision machining equipment and highly stable grinding slurry, the batch diameter variation that can be achieved is less than 0.08 μ m, exceeding the current international highest machining accuracy level G3 index.

Product application areas and solutions

1. Silicon nitride ceramic bearings and bearing balls
   Silicon nitride ceramic bearings are revolutionary products in the field of mechanical basic components. Compared to metal bearings, it performs excellently under harsh working conditions such as high speed, high temperature, vacuum, and corrosive media. Ceramic balls are lightweight (about 1/3 of bearing steel), have low centrifugal force, and can achieve ultra high speed operation; Simultaneously possessing self-lubricating properties, it can be used for a long time in highly polluted environments without lubricating media.
   Core application scenarios:
   -High speed precision spindle bearings: The highest manufacturing accuracy can reach P4 to UP level
   -New energy vehicle motor bearings: electrical insulation characteristics to prevent shaft current corrosion
   -Aerospace bearings: lightweight, resistant to high and low temperature alternation
   -Chemical corrosion-resistant bearings: can be used for a long time in seawater
2. Silicon nitride ceramic cutting tools
   Silicon nitride ceramic cutting tools are the third generation of ceramic cutting tools after aluminum oxide ceramic cutting tools, with higher toughness, impact resistance, and thermal shock resistance than previous generation products. Its excellent chemical stability and wear resistance can be used for long-term cutting under high-speed conditions, and its operating efficiency is more than three times higher than that of ordinary hard alloy cutting tools on average.
   Main applications: Suitable for rough machining, high-speed cutting, and heavy cutting of cast iron and high-temperature alloys, especially suitable for large-scale and efficient processing of cast iron parts such as automotive engine cylinder blocks and cylinder heads.
3. Silicon nitride ceramic turbine rotor
   The key component of a turbocharger is the turbine rotor. Traditional metal rotors have a large moment of inertia and slow response speed. Silicon nitride ceramic rotors have low density, high strength, and heat shock resistance, which can significantly improve the dynamic response performance of the turbocharger.
   Performance improvement: Experiments have shown that the rotational inertia of turbine rotors made of silicon nitride can be reduced by 40%, and the response time for turbocharging is 30% faster, significantly improving acceleration at low speeds and providing the possibility for lightweighting of automotive turbochargers.
4. Silicon nitride ceramic components for aluminum metallurgy
   Silicon nitride ceramics have excellent resistance to aluminum liquid corrosion and are widely used in aluminum casting and rolling production lines, as well as aluminum smelting and melting operations.
   Typical application: Thermocouple protective sleeves have long-term stable performance in aluminum liquid, and do not crack even after intermittent temperature measurement for more than 1200 times. Traditional stainless steel pipes can be corroded and damaged by aluminum liquid after only 20 hours of use, while corundum pipes cannot withstand thermal shock.
5. Key components of lightweight unmanned aerial vehicles
   Silicon nitride material is an ideal material for lightweight drones due to its density being only one-third of traditional steel and its ability to withstand extreme temperature differences and complex climates.
   Performance advantage: By implementing lightweight solutions, the flexibility and endurance of drones are enhanced, while also improving their stability in various complex environments.

Customization service for specifications and dimensions
We offer comprehensive customized solutions:
Diameter: 0.5mm -300mm
Length/height: 1mm -600mm
Surface roughness: Ra 0.2-0.8 μ m
Shape: ball, rod, plate, tube, irregular part
Features: through-hole, blind hole, thread, step, groove
We adopt various process routes such as hot pressing sintering, pressure sintering, and hot isostatic pressing, and recommend the optimal preparation plan based on your performance requirements and cost budget.

Customer Application Cases
Case 1: A well-known international new energy vehicle motor manufacturer (solving the problem of shaft current corrosion)
Customer demand: When the drive motor of the new energy vehicle produced by the enterprise runs at high speed, the shaft current generated by the variable frequency control will corrode the bearings, causing abnormal noise and early failure of the motor. The customer urgently needs a bearing solution that is both insulated and wear-resistant.
Solution: We have customized a full range of silicon nitride ceramic bearing balls for our customers, using hot isostatic pressing sintering technology, with a relative density of over 99.6%, batch diameter variation controlled within 0.06 μ m, and accuracy exceeding G3 level standards.
Final effect: After replacing with silicon nitride ceramic bearings, the problem of electrical corrosion of motor bearings was completely solved, and the motor life was increased from 80000 kilometers to over 300000 kilometers. The customer has made silicon nitride ceramic bearings standard on their high-end models, with an annual purchase volume of over 5 million pieces. This application has also become a benchmark case for the only domestic supplier of silicon nitride powder certified by the international electric vehicle industry chain.
Case 2: A precision machining enterprise (improving cutting efficiency and tool life)
Customer demand: This enterprise specializes in the processing of cast iron parts for automotive engines. Previously, it used hard alloy cutting tools, which required tool replacement for every 200 workpieces processed. Frequent shutdowns resulted in low production efficiency and high tool costs.
Solution: We recommend customers to switch to silicon nitride ceramic cutting tools and optimize the tool geometry angle and edge treatment based on their processing parameters.
Final effect: The number of workpieces machined with a single blade using silicon nitride ceramic cutting tools has increased to over 800, which is four times that of hard alloy cutting tools; The cutting speed has been increased from 300m/min to 800m/min, resulting in a nearly threefold increase in machining efficiency. The customer’s annual tool cost has decreased by 45%, and equipment utilization has increased by 30%.
Case 3: A certain unmanned aerial vehicle system research and development enterprise (solving the problems of lightweight and weather resistance)
Customer demand: The company is developing an industrial grade drone that can perform tasks in extremely cold regions and high-temperature desert environments. The bearing components are required to be lightweight while maintaining high precision and reliability within a temperature range of -50 ℃ to 80 ℃.
Solution: We provide our customers with high-end silicon nitride bearing balls and comprehensive solutions for weather resistance. After nine years of continuous research and development and over a hundred tests, we have finally achieved breakthroughs in material performance.
Final effect: Silicon nitride ceramic bearings reduce the weight of key components in drones by 60% and increase the overall endurance by 25%; Excellent performance in extreme temperature difference testing, without any lag or accuracy degradation issues. This project has been successfully selected as a demonstration project for the construction of cutting-edge technology application scenarios in 2025, becoming a model for the integration of new materials and low altitude economy.

Silicon nitride ceramics, as a cutting-edge material in the field of fine ceramic preparation, are reshaping the core components of high-end manufacturing with their excellent comprehensive performance. Whether it is in the motor bearings of new energy vehicles, key structural components of aerospace, or precision components of semiconductor equipment, silicon nitride ceramics are playing an irreplaceable role.
Welcome to contact us for samples or submit your drawings for sampling. Let’s work together to solve the most difficult industrial component problems and provide material support for your product upgrade!

Brudeze Ceramics supplies and sells a wide range of high-quality quartz glass, including alumina ceramics, zirconia ceramics, silicon nitride ceramics, aluminum nitride ceramics, silicon carbide ceramics, boron carbide ceramics, bioceramics, machinable ceramics, etc. We can meet the customization requirements of various ceramic products.