Nitride bonded silicon carbide

Nitride bonded silicon carbide (NB SiC) is a type of ceramic composite material that is formed by bonding silicon carbide (SiC) grains together using a nitride ceramic phase as the bonding agent. The properties of NB SiC can be tailored by adjusting the composition and processing parameters, such as the SiC-to-nitride ratio, temperature, and time of the nitridation process. 

NB SiC is produced through nitridation, where a mix of silicon carbide powder and a nitrogen-containing compound, such as silicon nitride (Si3N4) or ammonia (NH3), is heated to high temperatures in a nitrogen-rich atmosphere.  During the heating process, the nitrogen reacts with the silicon in the SiC grains, forming a silicon nitride phase that bonds the SiC grains together, resulting in a dense and mechanically strong composite material. 

Nitride Bonded Silicon Carbide characteristics

Thermal Shock Resistance

Nitride bonded silicon carbide has superior thermal shock resistance and can withstand rapid changes in temperature without cracking or fracturing, which makes it suitable for applications where the material is exposed to rapid temperature fluctuations or thermal cycling.

high temperature strength

Nitride bonded silicon carbide’s high temperature strength makes it suitable for use in applications that require materials to maintain their mechanical integrity and structural ability at elevated temperatures. The SiC provides high inherent mechanical strength and resistance to creep, oxidation, and corrosion at elevated temperatures, and the Si3N4 phase acts as a bonding agent, enhancing the materials fracture toughness and thermal shock resistance.

wear resistance

Nitride bonded silicon carbide is extremely hard, with one of the highest hardness values among engineering materials.  It is highly resistant to wear and abrasion from hard particles and surfaces.  Additionally, it has a low coefficient of friction, meaning that it has good lubricating properties and can reduce the friction between mating surfaces.

structural integrity

Nitride bonded silicon carbide provides good mechanical strength and toughness, even under heavy loads or impacts.  Additionally, it is chemically inert and resistant to most chemicals, including acids and alkalis, making it suitable for corrosive environments. 

Nitride Bonded Silicon Carbide Properties

Density (g/cc) Modulus of Rupture (MPa) Apparent Porosity (%) Max Use Temperature (°C) Coefficient of Thermal Expansion (1 x 10-6 in/in °C) Thermal Conductivity (W/mK)
2.60-2.72 65 13-16 1525 4.9 18

All properties are at room temperature (20°C) unless otherwise stated.

nitride bonded silicon carbide products

NB SiC is commonly used in the production of kiln furniture, which are the supports and structures used in high-temperature furnaces for firing ceramics, glass, and other materials.

NB SiC can be used in the production of metal casting components, such as crucibles and ladles, which are used for melting and casting of metals.

NB SiC can be used to produce wear-resistant components, such as seals, nozzles, tiles, and liners, for use in abrasive and erosive environments, such as in metallurgy, mining, and chemical processing.

NB SiC can be used to produce burner components, such as burner nozzles and flame holders, for high-temperature combustion processes.

NB SiC is used in the production of thermocouple protection tubes, which are used in high-temperature environments to protect thermocouples, which are temperature sensors, from harsh conditions.

 NB SiC can be used to produce refractory linings for furnaces and other high-temperature environments.

Frequently Asked Questions

Nitride bonded silicon carbide (NB SiC) is a ceramic material that is formed by reacting silicon powder with nitrogen gas at high temperatures in the presence of a sintering aid, typically magnesium. The reaction between silicon and nitrogen forms silicon nitride (Si3N4) while the sintering aid facilitates the densification of the material, resulting in a dense and high-strength ceramic.

Nitride bonded silicon carbide (NB SiC) is a ceramic material that is formed by reacting silicon powder with nitrogen gas at high temperatures in the presence of a sintering aid, typically magnesium. The reaction between silicon and nitrogen forms silicon nitride (Si3N4) while the sintering aid facilitates the densification of the material, resulting in a dense and high-strength ceramic.

NB SiC has excellent mechanical properties, including high strength, toughness, and wear resistance. It also has good thermal shock resistance and high-temperature stability, making it suitable for use in demanding applications where materials need to withstand harsh environments and high temperatures. NB SiC is also chemically resistant to many acids and alkalis, making it suitable for use in corrosive environments.

NB SiC is commonly used in applications where high strength, toughness, and thermal stability are required, such as cutting tools, wear parts, bearings, and nozzles. It is also used in aerospace and automotive applications, such as gas turbine components, engine parts, and heat exchangers, due to its excellent high-temperature performance. NB SiC is also used in specialized applications, such as in the semiconductor industry, due to its unique properties.

NB SiC is different from other silicon carbide ceramics, such as hot-pressed silicon carbide (HP SiC) or sintered silicon carbide (SSiC), in terms of its fabrication method. NB SiC is formed by a reactive process where silicon reacts with nitrogen gas, whereas HP SiC and SSic are formed by sintering of silicon carbide powders. NB SiC typically has lower density and slightly lower mechanical properties compared to HP SiC and SSiC, but it can offer advantages in terms of cost-effectiveness and ease of processing.

NB SiC Pricing Structure

  • Forming Method – the method used to produce the near net shape component
  • Machining Requirements – the type of tooling required and amount of machining necessary to achieve the final product
  • Component Details – the specifics of the end user’s components such as tolerance requirements
  • Quantity of Pieces

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