What are Silicon Carbide (SiC) ceramics?

Since the late 19th century, this compound of silicon and carbon, known as silicon carbide ceramics (SiC), has evolved from an abrasive powder to a cornerstone material for high-performance engineering. Today, SiC ceramics are indispensable in industries ranging from semiconductors and electronics to aerospace, automotive, energy and chemical processing.

What is silicon carbide? Scientifically, it is a covalently bonded silicon carbide compound with the chemical formula SiC that exhibits a unique crystal structure and can exist in different polytypes (3C, 4H, 6H). Its high hardness (Mohs 9.5), low density (~3.1 g/cm³), high melting temperature (~2,700 °C) and excellent thermal conductivity of silicon carbide make it ideal for demanding applications where metals or plastics fail.

At Zihao Ceramics, we offer engineered silicon carbide parts that are customized to provide unmatched precision, consistency and reliability.

jump to

dominance | appliance | Material Grade | characterization | case (law) | working (of machinery) | common problems | (statistics) correlation

Silicon Carbide Ceramics-Advanced Ceramic Materials-Zihao Ceramics

Advantages of Silicon Carbide Ceramics

The unique combination of mechanical, thermal and electrical properties makes SiC stand out among technical ceramics.

Silicon carbide has a Vickers hardness of approximately 22 GPa, which is close to the hardness of diamond and cubic boron nitride. This makes SiC ideal for wear parts, seals and abrasives.

With a density typically in the range of 3.02-3.15 g/cm³, silicon carbide offers excellent strength without being too heavy, an important advantage in aerospace and automotive systems.

With a thermal conductivity of over 100 W/m-K, SiC is an excellent material for heat exchangers, semiconductor wafers, and power electronic substrates.

A coefficient of thermal expansion (SiC CTE) of ~4 × 10-⁶/K ensures excellent dimensional stability, even with thermal shock and temperature fluctuations.

Resistant to acids, salts and most chemicals while forming a protective SiO₂ film above 1,300 °C to resist oxidation.

The electrical properties of silicon carbide allow it to be used as a wide-band semiconductor, making it ideal for high-power, high-temperature electronic devices.

Its combination of hardness, strength and corrosion resistance means that silicon carbide products perform significantly better than metals and polymers in harsh environments.

Industry Applications

The use of silicon carbide spans a wide range of industries due to its superior performance:

In aerospace, silicon carbide applications include turbine components, engine parts and thermal protection systems. Its high-temperature capabilities and lightweight properties make it ideal for these demanding environments. Silicon carbide ceramics are also used in armor protection systems for vehicles and personnel due to their superior hardness and lightweight properties.

The semiconductor properties of SiC have revolutionized power electronics. SiC technology enables more efficient power conversion, higher frequency operation and better thermal management than conventional silicon semiconductors. This makes it valuable for inverters, converters and power supplies in energy applications.

In industrial environments, silicon carbide products such as nozzles, seals, bearings and cutting tools provide excellent wear resistance and service life. The material's hardness and chemical inertness make it ideal for these demanding applications.

The automotive industry uses SiC for brake disks, clutch components and ceramic filters. In electric vehicles, SiC semiconductors are essential for power control systems to improve efficiency and reduce heat generation.

In semiconductor manufacturing, silicon carbide ceramics are used in wafer processing fixtures, sensitizers and plasma-resistant components. The material's purity, thermal stability and plasma resistance make it ideal for these critical applications.

Silicon carbide tubes, heat exchangers and reaction chambers provide excellent corrosion resistance in chemical processing environments. The material withstands corrosive acids, alkalis, and high temperatures, where metals degrade rapidly.

SiC's radiation resistance and high temperature stability make it suitable for nuclear applications, including fuel cladding and structural components in advanced reactor designs.

Types of Silicon Carbide Ceramics

At Zihao, we offer a wide range of high-performance silicon carbide materials optimized for the application to meet different engineering requirements:

Pressureless Sintered Silicon Carbide Ceramics (SSIC)

Pressureless Sintered Silicon Carbide Ceramics (SSiC) are high performance structural ceramics produced by a high temperature, pressureless sintering process. Their main component is high-purity silicon carbide powder. The sintering process does not require metal binders or external pressure, resulting in extremely high purity and density and thus excellent overall properties. This material is widely used in extremely harsh environments due to its excellent mechanical strength, wear and corrosion resistance.

Main features

  • Ultra-high hardness and wear resistance
  • With a Mohs hardness close to 9.5, second only to diamond and cubic boron nitride, SSiC has excellent wear resistance and is well suited for use in high friction and high wear environments.
  • Excellent mechanical strength: high flexural and compressive strength, even at high temperatures can maintain stable mechanical properties.
  • High Temperature Resistance: Can withstand long term stable operation in air environment above 1600°C and inert atmosphere above 1600°C.
  • Excellent corrosion resistance: excellent corrosion resistance to strong acids, strong bases and most organic solvents, suitable for use in corrosive environments.
  • Excellent thermal properties: high thermal conductivity, low coefficient of thermal expansion, excellent resistance to thermal shock, resistance to cracking caused by sudden temperature changes.
  • High purity and insulating properties: The pressureless sintering process eliminates the introduction of metallic impurities, resulting in high material purity while maintaining excellent electrical insulating properties.

typical application

  • Mechanical seals: sealing rings and bushings in pumps and compressors
  • Chemical equipment: corrosion-resistant piping, nozzles and valve linings
  • Semiconductor and electronics industry: high-temperature carriers, furnace tubes and linings
  • Wear-resistant components: bearings, wear-resistant linings and blast nozzles
  • Energy and environmental protection: photovoltaic industry furnace components, waste incinerator lining

Production process

Pressureless sintered silicon carbide ceramics are made from high-purity SiC powder, which is then formed into molds with a small amount of sintering aid and pressureless sintered at temperatures in excess of 2,000°C. The sintered silicon carbide ceramics are then sintered into molds with a small amount of sintering aid. This process gives the material a dense structure close to the theoretical density with fine, uniform grains, thus ensuring excellent overall performance.

Reaction Sintered Silicon Carbide Ceramics (SISiC)

Reaction Sintered Silicon Carbide Ceramics (SISiC) is a high performance ceramic material made from silicon carbide (SiC) powder and a carbon source. Liquid silicon is infiltrated into green objects at high temperatures, creating a reaction that produces new silicon carbide. Compared to pressureless sintered silicon carbide (SSiC), SISiC offers lower production temperatures and a more flexible process, enabling the fabrication of large and complex shaped structural components. As a result, it enjoys a wide range of industrial applications.

Main features

  • High hardness and wear resistance: SISiC has an excellent hardness (approximately 9 on the Mohs scale) and excellent wear resistance, making it suitable for friction and wear applications.
  • High mechanical strength: SISiC exhibits excellent flexural and compressive strength. Although lower than SSiC, it meets the requirements of most industrial applications.
  • Good corrosion resistance: SISiC is stable in most acidic and alkaline media and exhibits excellent oxidation resistance, making it suitable for use in the chemical industry.
  • Excellent thermal performance: SISiC has a low coefficient of thermal expansion, high thermal conductivity and excellent thermal shock resistance, enabling stable operation at high temperatures.
  • Ability to manufacture complex structures: The reactive sintering process is capable of producing large, thin-walled parts with complex geometries without the need for expensive hot pressing equipment.

typical application

  • Mechanical seals and pump components: sealing rings, bushings, pump impellers
  • Chemical equipment: corrosion-resistant lining, valves, nozzles
  • Thermal equipment: kilns, liners, supports
  • Energy: wear- and corrosion-resistant components for wind, thermal and nuclear power plants
  • Metallurgical industry: nozzles, channel liners and plain bearings

Production process

The process of preparing reactive sintered silicon carbide typically involves:

  1. Mixing silicon carbide powder with a carbon source to form a green body; and;
  2. High-temperature penetration of liquid silicon.;
  3. Liquid silicon reacts with carbon to form new silicon carbide, which densifies the green body.

Advantages of this method include process simplicity, low sintering temperatures, minimal dimensional shrinkage, and the ability to produce large, complex parts close to net size. However, the high temperature strength and oxidation resistance are slightly inferior to SSiC due to the presence of residual silicon.

Main Properties of Silicon Carbide

performances unit (of measure) unpressurized silicon carbide Reactive silicon carbide silicon nitride
color -- dark gray dark gray dark gray
intensity g/cm³ 3.15 3.02 3.2
porosity % ≤0.1 ≤0.1 --
durometer GPa 22 22 15
compressive strength MPa 2600 2600 2500
bending strength MPa 400 250 700
modulus of elasticity GPa 410 330 300
Maximum operating temperature ℃ 1400 1000 1100
heat conductivity W/(m・K) 100~120 45 (1200°C) 15~20
coefficient of thermal expansion 1 x 10-6/°C 4 4.5 3

*The above values are typical material properties and may vary depending on product configuration and manufacturing process. For more details, please feel free to contact us.

Chemical Properties of Silicon Carbide Materials

When the temperature in the oxygen reaction reaches 1300°C, a protective layer of silicon dioxide forms on the surface of the silicon carbide crystals. With the thickening of the protective layer, the internal silicon carbide is resisted and continues to combine, so that the silicon carbide crystal silicon carbide has good chemical resistance. In terms of corrosion resistance, SiC materials have strong acid resistance due to the role of the protective film of silica, but poor alkali resistance.

Silicon Carbide Ceramics Application Examples

Silicon Carbide (SiC) ceramics from Good Ceramics combine outstanding hardness, excellent thermal conductivity, superior wear resistance, and superior chemical stability, making them one of the most advanced ceramic materials for demanding industrial applications. With high melting points, low thermal expansion, and the ability to withstand extreme environments, SiC ceramics are ideal for industries that require durability, efficiency, and long service life.

Major applications of silicon carbide ceramics:

  • Mechanical seals and bearings
  • Aerospace components
  • Silicon Carbide Crucible
  • Semiconductor wafer carriers and substrates
  • Auto Parts
  • Nuclear energy and energy applications
  • Abrasives and cutting tools (diamond)
  • Heat exchangers and tubes
  • Electrons and electrical insulators
  • Customized Precision Ceramic Parts
Silicon Nitride Ceramic Bushing
Reactive Silicon Carbide Ceramic Bushings-Silicon Carbide Ceramics-ZhiHao Ceramics

Silicon Carbide Ceramics Processing

Silicon Carbide (SiC) ceramics are known for their extremely high hardness, high thermal conductivity and excellent wear resistance, making them one of the most challenging technical ceramics to machine. At Good Ceramics, we offer a full range of SiC machining services that provide industry-leading precision, performance, and reliability.

During the machining process, we utilize advanced diamond grinding, precision lapping and fine polishing techniques to achieve micron tolerances and superior surface finishes. These capabilities enable us to meet the stringent structural accuracy and surface quality requirements of mechanical seals, semiconductor substrates, crucibles, heat exchangers and aerospace components.

With years of technical expertise and state-of-the-art equipment, Grand Ceramics not only offers standardized silicon carbide parts, but also develops customized and complex components for specific industrial needs, ensuring high reliability and long service life under extreme operating conditions.

CNC grinding and milling

CNC milling, turning and grinding to micron tolerances.

Grinding and polishing

Surface polishing results in smooth surfaces and optical grade surfaces.

Laser processing of ceramic substrates

Ceramic Laser Cutting

For laser drilling and cutting of complex geometries.

Metal and Ceramic Brazed Assemblies - 600x600

Metallization and welding

Metallization (Mo/Mn, W) for ceramic-to-metal brazing.

Frequently Asked Questions

Silicon Carbide (SiC) is a synthetic compound of silicon and carbon known for its excellent hardness, thermal stability and chemical resistance. It rarely occurs in nature as the mineral moissanite, but is widely produced for industrial applications. The definition of silicon carbide includes simple compounds and advanced ceramic materials derived from them.

Yes, silicon carbide is a ceramic material, especially an advanced technical ceramic. Unlike traditional clay-based ceramics, silicon carbide is part of a class of materials known as “advanced,” “engineering,” or “technical” ceramics, which are characterized by excellent mechanical, thermal, and electrical properties. and electrical properties.

Silicon carbide is used in a wide range of applications including abrasives, refractories, ceramic armor, semiconductor electronics, heating elements and high temperature components. Specific applications for silicon carbide include mechanical seals, cutting tools, furnace components, power electronics and wear parts in industrial equipment.

silicon carbideare made by a variety of processes. The traditional Acheson method involves heating silica sand and carbon in an electric furnace to temperatures above 2200°C. For higher purity materials, chemical vapor deposition (CVD) is used. For higher purity materials, chemical vapor deposition (CVD) is used. To make solidSilicon Carbide CeramicsThe powder is molded and sintered at high temperatures (2000-2200°C) to achieve densification.

The electrical properties of silicon carbide vary widely. Pure SiC is an electrochemical semiconductor with a bandgap approximately three times wider than that of silicon. However, the electrical conductivity of silicon carbide can be altered by doping with specific elements. Some grades conduct electricity, while others are insulators. The conductivity of silicon carbide makes it valuable for electronic devices that operate at high temperatures, high frequencies, or high power levels.

Silicon carbide is very hard, with a Mohs hardness of 9.2-9.5, slightly lower than diamond (10) and boron carbide (9.5+). Its hardness is approximately 2500-2800 kgf/mm² (Vickers), making it one of the hardest materials commercially available. This extremely high hardness contributes to its excellent abrasion and wear resistance.

Silicon carbide has high mechanical strength, with flexural strengths typically in the range of 300-600 MPa. It retains this strength at elevated temperatures - at 1400°C it retains a room temperature strength of approximately 85%. Silicon carbide's strength, combined with its relatively low density, gives it an excellent strength-to-weight ratio compared to metals and other ceramics.

Related Products

Aluminum Nitride Ceramics

Aluminum Nitride Ceramics

Silicon Nitride Ceramics

Silicon Nitride Ceramics

Advanced Ceramics Manufacturing Specialist

Why choose us to produce silicon carbide ceramics?

  • Materials Expertise - In-depth knowledge of SiC characteristics ensures the best solution.
  • Advanced Manufacturing - Precision grinding and polishing for micron-level accuracy.
  • Customization - from standard parts to complex assemblies.
  • Quality Assurance - Rigorous testing for reliability and performance.
  • Global Reach - Trusted by industries around the world.

Contact today we

Ready to bring your ceramic designs to life?
Contact Chiho Ceramics for customized ceramic processing solutions that meet the highest standards for your application.