Nitride Bonded Silicon Carbide

NBSiC boasts high load carrying capacities at elevated temperatures, as well as being resistant to acids, molten salts and halogens. Furthermore, this low mass product can be formed into complex shapes to replace metal parts in various ways.

Material features excellent resistance to brittle cracking and impact wear. Furthermore, rubber has superior abrasive wear resistance than steels in every soil type.

Strength

NBSiC ceramics offer superior mechanical strength for applications in abrasive environments, as well as being chemically inert and resistant to acids. Furthermore, this refractory material has superb thermal stability – meaning it can withstand high temperatures without cracking or degrading – making them suitable for protecting thermocouples from harsh environments or creating furnace linings.

Strength is determined by grain size distribution and presence of silicon nitride particles between grains of silicon carbide. Tribological wear resistance decreases as grain sizes increase. With NBSiC, silicon nitride forms fine pore structures between large grains to allow reinforcement phase to re-attack abraded surfaces and decrease load on individual grains.

NBSiC can be formed into complex shapes using the Blasch process for use in refractory applications, as it is easily moulded. When formed into components it has an accuracy of up to several microns. Furthermore, NBSiC shows exceptional wear resistance against extreme temperatures as well as wear from soil particles, outperforming even special steels designed specifically for soil working, in wear tests showing nine times less intensive wear in medium soil conditions and up to 1.2 times less intensity in heavy soil conditions than steel wear tests showed.

Toughness

Nitride-bonded silicon carbide is an advanced refractory material with excellent toughness, abrasion resistance and strength properties. It can withstand extreme temperatures while remaining extremely stable with limited linear expansion and contraction rates as well as thermal shock resistance properties. Nitride bonded silicon carbide can often be seen used in iron-making blast furnaces (notably lower parts of stack, belly and bosh), ceramic manufacturing applications as well as other industrial uses.

Produced through the process of nitridation, silicon carbide (SiC grit and metallic silicon powder) are mixed and fired at high temperatures under nitrogen-rich environments to form reaction-bonded silicon carbide grains into dense ceramic materials with strong bonds similar to steel used for ceramic production.

Studies of nitride bonded silicon carbide have demonstrated its superior effectiveness at reducing abrasive wear than steel in various soil conditions, when compared with its performance against steel, boron steel and C+ Cr + Nb padding weld in various applications. Furthermore, grain size distribution was found to directly impact its wear resistance and wear resistance of this material.

As grain size decreases in nitride-bonded silicon carbide, its wear resistance increases and it becomes an ideal material to create parts for working soil mass.

Resistance to High Temperatures

Nitride-bonded silicon carbide exhibits excellent stability, mechanical strength and fracture toughness at temperatures exceeding 1375 degC (melting point of silicon). Silcarb uses an advanced production process for producing NBSIC Ceramics called slip casting/pressing followed by firing in an oxygen controlled environment to achieve the maximum service temperature possible. Nitride bonded silicon carbide finds multiple industrial uses including as kiln furniture sidewalls of aluminium melting pots or lower stacks in blast furnaces.

This material offers superior corrosion resistance in various environments, from dry air up to molten salts and metals, as well as complex environments like coal ash and slags. Nitride-bonded silicon carbide could even replace steel as the go-to choice in certain instances.

Nitride-bonded silicon carbide offers impressive wear resistance against abrasive soil conditions. Studies have demonstrated it to be up to nine times more resistant than special steels used for soil working, and more than twice as resistant as boron-containing steel used as padding weld on 38GSA steel. Performance in light soil conditions often outshone medium and heavy ones; especially beneficial is light versus medium heavy conditions.

Corrosion Resistance

Nitride-bonded silicon carbide is often utilized for applications that demand strength, toughness and thermal stability. This material is frequently found in wear parts, bearings and nozzles for wear resistance purposes; additionally it’s often seen used in aerospace and automotive applications including gas turbine components, engine parts and heat exchangers due to its excellent performance at high temperatures.

Nitride in the bonding phase provides protection from corrosion by hot gases, molten salts and metals. Materials often receive an additional coating of silica to further increase their corrosion resistance while protecting silicon carbide from erosion while improving overall corrosion resistance. Nitride also contributes to thermal shock resistance so they can be used effectively for applications that involve rapid temperature changes.

Nitrogen-bonded silicon carbide (NBC) refractories are often employed in severe service conditions to replace alloys and other forms of refractories such as alloyed material. Common examples include cyclone liners for mineral processing plants as well as pump components, valve linings, spigots and nozzles made out of cast refractory materials containing NBC.

Nitrogen-bonded silicon carbide bricks have numerous applications in steel and nonferrous metallurgy furnaces for use as sidewalls and bottom stacks of aluminium melting pots, blast furnaces, kiln furniture and blast furnaces. Their characteristics include excellent impact resistance, the ability to be formed into complex shapes easily and an exceptional abrasion resistance rating.

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