Silicon Carbide-based Nitride Bonded Silicon Carbides (NBSIC) are used for their good thermal, mechanical and wear resistance attributes. Although heating at high temperature and pressure can produce sintered pure silicon carbide, the process commercially viable. High-density silicon carbide materials are produced by introducing a bonding aid that produces a secondary phase. The thermomechanical properties are then often limited by the properties of the secondary bond. For example, the maximum operating temperature of Silicon Impregnated SIC (SISIC/RBSIC) Bonded Silicon Carbide is 1375°C, the melting point of silicon.
Silcarb manufactures its NBSIC in a very controlled electric furnace where temperatures are very accurately maintained and pressures are regulated through the cycle. Silcarb has a battery of furnaces in its Bangalore plant, which manufactures a number of shapes, sizes, and profiles of nitride-bonded silicon carbide.
Silcarb manufactures these Kiln Furniture by a number of forming processes:
The required forming process is adapted for specific products.
The properties of nitrogen-bonded silicon carbide suit many harsh service conditions:
Silcarb makes its NBSIC in various percentages of silicon. The lowest percentage of being 10%, going all the way up to 38% silicon with additions of aluminum oxides for molten metal applications.
Table 1. Typical mechanical and thermal properties for silicon nitride (20-30%) bonded silicon carbide (70-80%).
| Property | |
|---|---|
| Density | 2.69 |
| Porosity (%) | 14 |
| Young’s Modulus | 80 |
| Bending Strength (MPa) | 38 |
| Thermal Expansion Coefficient (x 10-6/ºC) | 2.7 |
| Thermal Conductivity (W/mK) | 32 |
| Maximum Operating Temperature (ºC) | 1600 |
Note:- The properties of NBSIC Ceramics manufactured by Silcarb vary based on application. Do get in touch for specific figures.
Exploiting the material’s excellent stability and mechanical strength, nitrogen-bonded silicon carbide bricks are used in a range of process furnaces and kilns, such as the sidewalls of aluminum melting pots, the lower stack of blast furnaces, and as kiln furniture.
Nitrogen-bonded silicon carbide is commonly found as a cast refractory for use under severe service conditions in place of alloys or other refractory materials. Near net shapes can be designed to reproduce the metal parts. The high hardness and abrasion resistance of the material mean that components should be designed to avoid grinding or other finishing operations.
Applications of cast refractories exploit the physical and chemical properties of the material and the ability to form the material into complex shapes.
Current products produced by Silcarb in NBSIC
Get in touch for any shapes or sizes of NBSIC products; we can make a single piece for you if needed.
We have an in-house die and tool design, manufacturing team and can make any complex shapes you need.
Nitride Bonded Silicon Carbide (NBSIC) Kiln Furniture is used in high-temperature industrial furnaces and kilns where extreme thermal shock resistance, high load-bearing capacity, chemical inertness, and long operational life are required. These products are particularly suited for aluminum melting, non-ferrous metal handling, abrasive environments, and aggressive chemical processing applications.
