Silicon nitride-bonded silicon carbide bricks, as a high-performance refractory material, play an important role in industrial high-temperature applications due to their unique properties. This article will introduce their core characteristics and application scenarios.
1.Core properties of silicon nitride bonded silicon carbide bricks
Silicon nitride bonded silicon carbide bricks use silicon carbide (SiC) as the main aggregate and silicon nitride (Si₃N₄) as the binding phase. The two react at high temperature to form a dense structure. It mainly has the following characteristics.
Silicon nitride bonded silicon carbide brick
First, its compressive strength at room temperature can reach 150-200MPa. Its hardness is second only to diamond, and its wear resistance is significantly better than traditional refractory materials.
Secondly, it has a low coefficient of thermal expansion and excellent thermal shock resistance. This allows it to withstand extreme temperature fluctuations without cracking.
In addition, it has outstanding chemical stability and is resistant to acid and alkali corrosion. Especially in reducing atmosphere, it is more stable and less likely to react with molten metal or slag.
2.Key performance advantages
On the one hand, silicon nitride bonded silicon carbide bricks have high high temperature structural strength. It can still maintain good mechanical properties at around 1400℃ and will not deform during long-term use.
On the other hand, its thermal conductivity is 15-20W/(m·K), much higher than clay bricks or high-alumina bricks. Therefore, it can quickly transfer heat and improve the thermal efficiency of equipment.
Silicon nitride bonded silicon carbide bricks
At the same time, its apparent porosity is low, which can effectively block slag penetration and extend service life.
In addition, it has good oxidation resistance, and the SiO₂ protective layer generated on the surface at high temperature can further prevent the oxidation process.
3.Main industrial application areas
Silicon nitride bonded silicon carbide bricks are widely used in high-temperature industrial scenarios.
Metallurgical field. Commonly used in the lower portion of blast furnace shafts and hot blast furnace domes. Its high-temperature resistance and slag-corrosion resistance make it suitable for harsh working environments.
In the ceramic industry, it is often used as kiln furniture (such as shelves and pillars) and kiln linings. Its high thermal shock resistance can meet the needs of frequent temperature increases and decreases.
Silicon nitride bonded silicon carbide bricks
Chemical industry, it is used for lining waste incinerators and chemical reactors. Its corrosion resistance can ensure the long-term stable operation of the kiln.
In the field of non-ferrous metal smelting, this brick is suitable for the side walls of aluminum electrolytic cells, zinc smelting distillation tanks, etc., and can effectively resist erosion by molten metal.
