What are the remarkable properties of silicon carbide ceramics?
Publish Time: 2025-03-04
As a high-performance structural ceramic material, silicon carbide ceramics have shown irreplaceable application value in many industrial fields due to their unique physical and chemical properties. The following is a detailed description of the remarkable properties of silicon carbide ceramics.
Silicon carbide ceramics have excellent high-temperature strength. Under high-temperature environments, the strength of ordinary ceramic materials usually decreases significantly, while silicon carbide ceramics can still maintain high bending strength at 1400 degrees Celsius, and its operating temperature can even reach 1600~1700 degrees Celsius. This feature makes silicon carbide ceramics particularly widely used in high-temperature environments, such as high-temperature bearings, nozzles, and high-temperature corrosion-resistant parts.
Silicon carbide ceramics also show excellent oxidation resistance. When silicon carbide material is heated to a certain temperature in air, a dense silicon dioxide protective layer will form on its surface. This protective film can effectively inhibit the further diffusion of oxygen, thereby slowing down the oxidation rate of silicon carbide. Therefore, silicon carbide ceramics have good working stability in an atmosphere containing oxidants.
In addition, silicon carbide ceramics have extremely high hardness and wear resistance. Its Mohs hardness is as high as 9.2, close to superhard materials such as diamond, cubic boron nitride and boron carbide. This feature gives silicon carbide ceramics a significant advantage in wear-resistant and erosion-resistant parts, such as wear-resistant pipes and wear-resistant plates. At the same time, silicon carbide ceramics are also very corrosion-resistant and can withstand the erosion of a variety of strong acids and alkalis, which makes it have a wide range of application prospects in the fields of chemical industry and environmental protection.
Silicon carbide ceramics also have good thermal stability and thermal conductivity. Its thermal expansion coefficient is small, its thermal shock resistance is high, and it can maintain stable performance under extreme temperature conditions. In addition, the thermal conductivity of silicon carbide ceramics is also high, second only to beryllium oxide ceramics, which makes it important in high-temperature and high-frequency electronic equipment components.
However, silicon carbide ceramics also have certain brittleness problems. Due to the high hardness and brittleness of silicon carbide ceramics, it is easy to break and crack during processing. Therefore, when processing silicon carbide ceramics, it is necessary to use high-precision processing equipment such as dedicated ceramic engraving machines to ensure processing accuracy and product quality.
Silicon carbide ceramics also exhibit good electrical properties. It is a semiconductor material at room temperature and has impurity conductivity. As the temperature rises, the resistivity of high-purity silicon carbide decreases. This feature makes silicon carbide ceramics have potential application value in the electronics field, such as the production of fixture materials in semiconductor wafer preparation.
In summary, silicon carbide ceramics have remarkable characteristics such as excellent high-temperature strength, excellent oxidation resistance, extremely high hardness and wear resistance, good thermal stability and thermal conductivity, and good electrical properties. These characteristics make silicon carbide ceramics increasingly widely used in many fields such as automobiles, mechanical chemicals, environmental protection, space technology, information electronics, and energy, becoming an indispensable high-performance material.
