Is the superior performance of silicon carbide ceramics parts characterized by the advantage of high hardness?
Publish Time: 2024-11-29
Silicon carbide ceramics parts are indeed known for their excellent performance, with high hardness being one of their significant advantages.
1. High hardness
Hardness value: The hardness of silicon carbide (SiC) is very high, and its Vickers hardness (Vickers hardness) is usually between 27-32 GPa, close to or exceeding many other ceramic materials, such as alumina (Al2O3) and silicon nitride (Si3N4 ).
Wear resistance: High hardness gives silicon carbide ceramics excellent wear resistance, allowing them to perform well in friction and wear environments.
2. High temperature performance
High melting point: The melting point of silicon carbide is approximately 2730°C, allowing it to maintain stability and strength in high temperature environments.
Thermal conductivity: Silicon carbide has high thermal conductivity (about 120-270 W/m·K), which helps to dissipate heat quickly and reduce thermal stress.
3. Chemical stability
Corrosion resistance: Silicon carbide has good corrosion resistance to many acids, alkalis and solvents, especially in high temperatures and corrosive environments.
Oxidation resistance: In a high-temperature oxidizing environment, a protective oxide film will be formed on the surface of silicon carbide, thereby improving its antioxidant capacity.
4. Mechanical strength
High Strength: Silicon carbide ceramics have high flexural strength (approximately 300-600 MPa) and compressive strength (up to 2000 MPa), making them perform excellently under mechanical stress.
Fracture toughness: Through reasonable manufacturing processes, such as hot-press sintering and chemical vapor deposition (CVD), the fracture toughness of silicon carbide ceramics can be improved and the risk of crack expansion can be reduced.
5. Low density
Lightweight material: Silicon carbide has a relatively low density of approximately 3.2 g/cm³, making it a lightweight and high-strength material suitable for lightweight designs.
6. Electrical properties
High Resistivity: Silicon carbide has a high resistivity and is used to make insulating materials.
Semiconducting Properties: Some silicon carbide materials have semiconducting properties, making them suitable for applications in electronic and power equipment.
7. Application areas
Mechanical parts: Due to their high hardness and wear resistance, silicon carbide ceramics are widely used in the manufacture of pumps, valves, bearings, seals and other mechanical parts.
Chemical equipment: In the chemical industry, silicon carbide ceramics are used to manufacture corrosion-resistant equipment such as reactors, pipes, and containers.
Thermal equipment: Due to its excellent high-temperature performance, silicon carbide ceramics can be used to manufacture high-temperature stoves, burners, heat exchangers, etc.
Electronic devices: The high resistivity and thermal conductivity of silicon carbide ceramics make them suitable as substrates and packaging materials for manufacturing electronic devices.
Aerospace: The lightweight and high-strength properties make it useful in the aerospace field, such as manufacturing high-temperature structural parts and wear-resistant parts.
8. Manufacturing process
Hot Pressing: Sintering silicon carbide powder into dense ceramic parts under high temperature and pressure.
Chemical vapor deposition (CVD): A high-purity silicon carbide layer is formed on the surface of the substrate through vapor deposition technology.
Reaction Bonding: By adding silicon powder to react with silicon carbide powder during the sintering process, dense silicon carbide ceramics are formed.
To sum up, the high hardness advantage of silicon carbide ceramics parts is not only reflected in its wear resistance, but also in its comprehensive mechanical, thermal, chemical and electrical properties. These characteristics give it broad application prospects and significant advantages in multiple industrial fields.
