Silicon Nitride bonded Silicon Carbide Products—Refractory Materials

Silicon carbide is a synthetic, advanced inorganic non-metallic material,  combined by the covalent, with hardness second only to diamond, melting point at 2600℃, and 3.21g/cm3 for true density. The thermal conductivity rate reaches up to 8.37W/m · k. The melting point of silicon nitride is 1900℃, the Mohs hardness 9, the density 3.19 g/cm3, and the thermal conductivity is 15W / m·k.

The silicon nitride bonded silicon carbide is a new high-performance refractory product with a combination of both properties. The chemical properties are stable. The flexural strength at normal temperature is 4-8 times that of ordinary refractory materials, and 2-3 times that of traditional silicon carbide products (clay-bonded silicon carbide). The thermal conductivity is 7-8 times that of general refractory materials double that of traditional silicon carbide. The thermal expansion coefficient is half the general refractory materials.

Practice has proved that silicon nitride bonded silicon carbide products (150×150×15) can be directly water-cooled for 30 times at 1100℃ without cracks. They  have better thermal shock resistance, high-temperature creep resistance, acid resistance, alkali resistance, excellent oxidation resistance, resistance to corrosion of such molten metal as aluminum (Al), lead (Pb), tin (Sn), zinc (Zn), copper (Cu), good electrical insulation, high specific resistance at room temperature. Silicon nitride bonded silicon carbide replacing the traditional silicon carbide products can reduce  the weight of kiln furniture by 50%, increase the loading rate by 16%, and save energy by more than 15%. They are ideal refractory materials for enterprises to improve product quality and increase economic efficiency.

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