Nitride Bonded Silicon Carbide

Nitride-bonded silicon carbide with superior high-temperature strength and excellent oxidation resistance makes an ideal material for kiln furniture applications.

Nitride-bonded silicon carbide of the present invention is particularly resistant to abrasive wear in soil masses. Wear resistance was determined to depend on grain size distribution within the mass worked; for best performance in light soil.

High Strength

Nitride-bonded silicon carbide’s superior strength makes it an ideal refractory material to use in iron-making blast furnaces, withstanding even harsh conditions like pressure sintering. This material is produced by reacting silicon carbide powder with nitride or oxide ceramics in a pressure sintering process; the end product being dense material with very high tensile and compressive strengths while having very few pores.

Bricks with this composition can withstand thermal shock, making them suitable for use in iron-making blast furnaces’ lower part of stack, belly, bosh and tuyere areas. Furthermore, their properties include excellent slag resistance, high temperature wear resistance and alkali erosion resistance.

Silcarb ceramics provide excellent resistance to oxidisation and toughness for applications that demand it – such as thermocouple protection tubes used in harsh environments to shield temperature sensors from damage. Silcarb offers nitride bonded silicon carbide ceramics specifically tailored for such purposes that are produced for thermocouple protection tubes by Silcarb.

Nitride-bonded silicon carbide bricks also possess impressive impact and abrasive wear resistance in light soils, as demonstrated in a study that concluded they had greater anti-wear properties than steel and the Fe-Cr-Nb padding weld used on 38GSA steel. Unfortunately, its wear resistance decreases substantially in heavier soil conditions as abrasive particles tend to lodge themselves within its pores more readily than expected.

High Temperature Strength

Nitride-bonded silicon carbide has the unique capability of withstanding extreme temperatures due to the nitridation reaction which forms highly covalent bonds between silicon powder and the nitride particles, maintaining strength even under challenging circumstances such as oxidation at extremely high temperatures.

Nitride-bonded silicon carbide boasts a high specific strength that makes it suitable for a range of applications. Furthermore, this material boasts exceptional tribological properties and wear resistance; impact shock is handled well thanks to high fracture toughness; corrosion protection is excellent while thermal shock resistance makes this an excellent option for industrial uses.

At 25 C and 1300 C, fiber reinforced, unidirectional nitride-bonded silicon carbide was tested using a new testing technique that minimizes bending moment while guaranteeing failure always occurs within the gage section of specimen. Results demonstrated metallike stress-strain behavior at both temperatures with an ultimate tensile strength reaching 543 MPa at 1300 C.

Wear characteristics of nitride-bonded silicon carbide depend on the soil mass type, particularly particle size distribution. Light soil showed superior wear resistance while heavy soil recorded the lowest value for wear resistance.

High Temperature Resistance

Nitride-bonded silicon carbide exhibits superior thermal stability at elevated temperatures, as it is resistant to cracking at higher temperature levels. This makes it an excellent refractory material choice when exposed to rapid changes in operating conditions – perfect for applications which involve rapid transitions.

Reaction bonded silicon carbide (RBSC) is created through pressure sintering of a mixture of SiC and oxide ceramic powders containing aluminium. The resultant dense matrix of SiC boasts excellent wear, impact and chemical resistance while being easily formed into intricate shapes with the Blasch process.

Nitride-bonded refractories are highly stable materials with exceptional mechanical strength, thermal shock resistance, chemical inertness and chemical inertness – qualities which have seen it used across a range of industrial applications such as sidewalls of aluminium melting pots and lower stacks of blast furnace bells, as well as in kiln furniture such as burners, muffles, shed board push boards rafts and pillars due to its superior temperature strength and mechanical integrity.

Nitride bonded sinter is known for its superior abrasion resistance. Studies have demonstrated its far superior wear performance over steels and padding weld in all soil types tested, more than doubling steel’s resistance in light soil conditions and tripling its resistance in heavy ones.

Thermal Shock Resistance

Nitride-bonded silicon carbide offers excellent thermal shock resistance, withstanding rapid temperature changes without cracking – making it the ideal material for applications that experience thermal cycling. Nitride bonded silicon carbide also boasts outstanding high-temperature oxidation resistance due to its dense surface which resists gas oxidation from gases such as metal oxides or alkaline solutions as well as cryolite corrosion, making it suitable for waste incineration applications, aluminium reduction cells or copper shaft furnaces.

Reaction-sintered silicon nitride (RSiC) technology allows its creation. Silicon powder is mixed with grains of silicon carbide before being exposed to nitrogen gas for nitriding in an atmosphere rich with solid silicon particles, producing silicon nitride which bonds the silicon carbide particles together to form dense material, producing porous structure with lower density than liquid phase sintered silicon carbide (LPSSIC).

NBSiC can be easily formed into intricate shapes using the Blasch process and has desirable refractory and chemical properties. Its wear resistance even in harsh abrasive soil conditions has proven impressive – wearing out far less intensively than special steels intended for soil working, in some tests by four times (versus weld pads with Fe-Cr-Nb padding welds in medium soil conditions and up to 6.5 times in heavy soil conditions).

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