ADVANTAGES AND DISADVANTAGES OF SILICON CARBIDE MATERYALS FOR SEALS

In the modern industrial field, seals play a crucial role. They can prevent the leakage of fluids or gases and ensure the normal operation of the equipment. As a high-performance sealing material, silicon carbide material is gradually receiving wide attention.

1. Advantages of silicon carbide materials

1). Excellent wear resistance

Silicon carbide has extremely high hardness, and its Mohs hardness is as high as 9.2, second only to diamond and cubic boron nitride. This enables silicon carbide seals to show excellent wear resistance in the face of high-speed rotation, high pressure and fluids containing solid particles, which greatly extends the service life of seals. For example, in the petrochemical industry, pump seals often need to handle media containing hard particles such as gravel. Silicon carbide seals can effectively resist the wear of these particles and ensure the stability of sealing performance.

2). Good chemical stability

Silicon carbide hardly reacts with any chemicals at room temperature and has excellent corrosion resistance. Whether it is strong acid, strong alkali or organic solvent, it is difficult to cause damage to silicon carbide seals. This characteristic enables silicon carbide seals to work reliably in various harsh chemical environments. For example, in the pharmaceutical industry, some drugs are strongly corrosive. Silicon carbide seals can ensure that the equipment will not leak due to corrosion during production, and ensure the quality and production safety of drugs.

3). Excellent high temperature resistance

Silicon carbide can maintain stable performance in high-temperature environments. Its high-temperature resistance can reach more than 1600℃, which makes silicon carbide seals widely used in high-temperature equipment such as high-temperature industrial furnaces and engines. In these high-temperature environments, ordinary sealing materials tend to soften, deform or even fail, while silicon carbide  seals can always maintain a good sealing effect to ensure the normal operation of the equipment.

4). High mechanical strength

Silicon carbide material has high mechanical strength and can withstand greater pressure and impact. This enables silicon carbide seals to maintain a stable structure under high pressure, high speed and other harsh working conditions, and will not be easily damaged. For example, in high-pressure valves, silicon carbide seals can withstand a huge pressure difference to ensure the sealing performance of the valve.

2. Disadvantages of silicon carbide materials

1). The cost is high.

Compared with traditional sealing materials, the production cost of silicon carbide is higher. This is mainly because the preparation process of silicon carbide is complex, which requires special conditions such as high temperature and high pressure, and the price of raw materials is also relatively high. This makes silicon carbide seals more expensive and limits their application in some cost-sensitive fields.

2). It is difficult to process.

The hardness of silicon carbide is extremely high, which also brings great difficulties to its processing. The processing of silicon carbide seals requires the use of special tools and processing equipment. During the processing process, the tool wears quickly and the processing efficiency is low. In addition, silicon carbide is also relatively brittle, and it is easy to have cracks and other defects during the processing process, and the requirements for the processing process are very strict.

3). High requirements for installation

Due to the high hardness and brittleness of silicon carbide seals, the installation requirements are also relatively high. During the installation process, if it is operated improperly, it is easy to damage the seal. For example, if the sealing surface is uneven and the installation force is too large during installation, the silicon carbide seal may crack or break, thus affecting the sealing performance.

In summary, the silicon carbide material used in seals has the advantages of excellent wear resistance, chemical stability, high temperature resistance and mechanical strength, but it also has the disadvantages of high cost, high processing difficulty and high installation requirements. In practical application, we need to comprehensively consider the advantages and disadvantages of silicon carbide materials according to specific working conditions and requirements, and choose appropriate sealing materials to ensure the sealing performance and operation safety of the equipment. At the same time, with the continuous progress of science and technology, it is believed that the preparation process and processing technology of silicon carbide materials will continue to improve in the future, and the cost will be gradually reduced, so that it will be more widely applied in more fields.