High-performance Silicon Carbide Mechanical Seal Rings and SiC Bases

Silicon carbide ceramic mechanical seal rings are high-performance sealing components made primarily from high-purity silicon carbide (SiC). They are manufactured through high-temperature sintering and precision machining. Their core features include ultra-high hardness, exceptional wear resistance, and excellent high-temperature and corrosion resistance. They are widely used in the petrochemical, nuclear power, aerospace, and high-end pump and valve industries.

Silicon carbide ceramic mechanical seal rings are made from high-performance silicon carbide (SiC) material. Due to its exceptionally high comprehensive performance, they are often used to solve the most challenging and demanding sealing problems, making them a benchmark material for high-end sealing applications.

Silicon carbide's performance is virtually tailor-made for mechanical seals, offering comprehensive advantages:

1. Extremely high hardness and exceptional wear resistance. With a Knoop hardness of 2500-2800 kg/mm², it is one of the hardest materials in the world. This means it is extremely wear-resistant and effectively resists erosion and wear from solid particles in the medium (known as abrasive wear), resulting in an extremely long service life.

2. Excellent thermal performance.

• High thermal conductivity: Its thermal conductivity is very high (approximately 80-200 W/m·K), even exceeding that of some metals. This allows it to quickly dissipate heat generated by the friction pair, preventing excessive temperatures on the seal faces that could lead to liquid film vaporization, dry friction, and thermal cracking. 
• Low thermal expansion coefficient: Dimensional change is minimal when heated, ensuring the seal face's shape and fit remain stable even when the operating temperature fluctuates, preventing failure due to thermal deformation.
• Excellent thermal shock resistance: Combining high thermal conductivity with low thermal expansion, it can withstand rapid temperature fluctuations without cracking.

3. Excellent chemical resistance.Resistant to strong acids (such as hydrochloric acid, sulfuric acid, and nitric acid), strong bases, saline solutions, oxidants, and organic solvents. Its corrosion resistance is second only to graphite, but its strength is far superior. Exceptional: It is not resistant to strong oxidizing acids such as hydrofluoric acid, fuming nitric acid, and hot concentrated phosphoric acid.

4. High strength and good rigidity. It has high flexural strength and can withstand high pressures without deformation or fracture.

The most widely used material is pressureless sintered silicon carbide (SSiC). Its manufacturing process involves sintering at high temperatures without pressure and using sintering additives. It is characterized by the highest purity, best corrosion resistance, high hardness, and optimal overall performance. This is the most commonly used and most comprehensive type of silicon carbide, suitable for most demanding working conditions.

1. Chemical and Petrochemical Industry
Applications: Mechanical seals for equipment such as centrifugal pumps, reactors, and compressors; valve seals for conveying corrosive media (such as strong acids and alkalis)

2. Energy and Power

• Nuclear Power Plants: Main circulation pump seals, which must withstand high-temperature water temperatures exceeding 300°C and radiation environments
• Fuel Power Generation: Boiler feedwater pumps and flue gas desulfurization (FGD) system seals, resisting fly ash abrasion and acid corrosion
• Advantages: Strength exhibits minimal degradation below 1600°C, significantly superior to carbon graphite seals (limited to 400°C)

3. Healthcare

• Precision Surgical Instruments: Ceramic scissors offer a cutting edge five times sharper than stainless steel instruments
• Implants: Artificial joint wear is reduced by 99%, achieving a clinical lifespan of up to 20 years
• Sterilization Equipment: Withstands repeated sterilization with high-pressure steam at 121°C without deformation

4. Semiconductor Manufacturing

• Wafer Processing: Lining the reaction chambers of etching equipment, non-reactive with corrosive gases
• Photolithography: The worktable guide rails have a thermal expansion coefficient of only 3.8 × 10⁻⁶/°C, ensuring nanometer-level precision
• Advantages: Avoids iron contamination, ensuring a clean chip manufacturing environment

5. Other High-End Applications

• Aerospace: Rocket engine seals. The Chang'e-5 lunar exploration project used boron carbide ceramic seal rings with a lifespan of 90,000 hours.
• Deep-sea Equipment: Resistant to high-pressure saltwater corrosion, providing stable sealing performance
• New Energy: Hydrogen fuel cell bipolar plates, with a thermal conductivity 30% higher than traditional graphite