Different Types of Silicon Carbide and Related Materials

Silicon Carbide (SiC) is an extremely hard, crystalline chemical compound made of silicon and carbon that occurs naturally as moissanite gemstone, but most often produced as powder for use as an abrasive, in refractories and ceramics due to its outstanding resistance against both high temperatures and corrosion.

Nitride Bonded Silicon Carbide

Nitride Bonded Silicon Carbide (NBSC) is an essential refractory material in many applications. With high resistance to wear, corrosion, and wetting by non-ferrous metals such as aluminum electrolysis cells, copper shaft furnaces, and waste incinerator plants. Furthermore, this refractory has excellent thermal conductivity to withstand high temperatures without warping or cracking under stress.

NBSCs are created through direct nitridation of SiC particles and silicon powder in controlled nitrogen environments. The process occurs at temperatures just below SiC’s melting point to ensure all individual components fuse properly, creating an extremely strong and durable ceramic substance. Once completed, this bonded material must be heated to sintering temperatures where its strength will become evident.

Nitride Bonded Silicon Carbide manufacturing process allows for greater precision when selecting particle sizes, leading to enhanced strength and durability of this refractory material. As a result, resistance against impact wear increases significantly while its dense structure increases thermal conductivity as well as resistance against oxidation.

Nitride-bonded silicon carbide’s ability to manage extreme temperatures and tolerate thermal shock makes it ideal for creating components for industrial furnaces such as kiln furniture. Furthermore, this material makes an excellent lining choice; unlike sintered silicon carbide which brittles at higher temperatures.

NSiC comes in many forms, such as thin-wall batts, tubes, burner nozzles and beams with different cross sections. It boasts greater bending strength than RSiC while boasting superior oxidation resistance against copper, zinc, aluminum and lead alloys.

Nitride Bonded Silicon Carbide shelves are highly resilient and long-term, even under heavy loads or impacts, thanks to expansion joints which help reduce stress on the shelf during expansion/contraction cycles of kilns while avoiding cracking. They’re resistant to most chemicals and alkalis corrosives environments making them ideal for corrosion resistant environments; however, care must be taken when handling these shelves, since loading or unloading while the electric kiln is running may lead to an electric shock hazard!

ALTRON® Alumina Bonded Silicon Carbide

ALTRONTM is a revolutionary material created specifically to meet the high wear and corrosion demands of coal fired power plant applications, such as corrosion protection for turbine blades. As a ceramic that combines oxide-bonded, nitride-bonded, and alumina bonded SiC characteristics with their advantages – its cost effectiveness makes ALTRON an economical solution that can be formed into complex shapes without incurring traditional hard tooling setup charges.

This unique method for producing alumina-silicon carbide refractory products entails mixing an abrasive silica sand or blast furnace granule with reaction bonded silicon carbide powder, yielding an intergrowth texture composed of corundum and silicon carbide with improved hot strength, thermal shock resistance and chemical resistance properties. Alumina bonded silicon carbide (AB SiC) products can be manufactured into various sizes and shapes including pumps components, mechanical seals bearings as well as flow control chokes cyclones chutes among many others for wear components manufacturing purposes.

Precision cut from large, complex shapes made of ceramic material is precision cut into complex shapes to replace several separate components into one integrated assembly. Ceramic often outlives existing metallic parts in power plants and reduces downtime for maintenance and replacement costs, such as replacing FCC air grid nozzles made of ALTRON every two or three years with ceramic units which outlast them by 200% or more.

Comparative to nitride-bonded silicon carbide brick and other sintered ceramics, ALTRON exhibits greater inherent strength, good creep resistance, superior toughness and one of the highest hardness values among engineering materials; its hardness also aids resistance against abrasion from sharp particles or surfaces and impact from sharp particles or surfaces. Furthermore, unlike many ceramics it can withstand higher temperatures without degradation thanks to its mixture of alumina and boron which serve as barriers against oxidation.

InVinCer® by Blasch Reaction Bonded Silicon Carbide

Blasch Reaction Bonded Silicon Carbide’s InVinCer(r), an advanced ceramic material with excellent wear and chemical resistance up to its maximum use temperature of 1380AdegC, comes in various shapes, sizes and configurations for various applications. Engineered specifically for Power Generation, Smelting (Pyrometallurgy) and refining industries – InVinCer(r) Nozzles come in CFB – Circulating Fluidized Bed or BFB Bubbling Fluidized Bed designs which allow various applications including gas cooling, particulate removal, Atomization Vortexing or spraying applications – threaded or other mounting configurations are also available.

Reaction Bonded Silicon Carbide, commonly referred to as RB SiC, is one of the hardest and most durable of refractory ceramics. Its hardness remains unchanged even at elevated temperatures, offering superior wear resistance, corrosion protection and thermal shock resistance as well as very high strength at half of steel’s weight. ULTRON, Nitron, Invincer by Blasch RBSC and Oxytron products from this material can all be found widely used applications across several fields.

Reaction-bonded silicon carbide stands out as an excellent refractory material that retains its physical properties at extremely high temperatures without degradation or loss of mechanical characteristics, making it an excellent option for critical power generation and industrial process heating applications.

With a maximum use temperature of 1,380AdegC, RB SiC offers extremely low maintenance and operating costs compared to other refractory ceramics. Due to its superior mechanical properties that enable thinner walls and smaller diameters resulting in significant cost savings for users. Furthermore, this material comes in various shapes, sizes, configurations and configurations suitable for many industrial applications including micronizers, cyclone separators, pump components, crucibles mechanical seals or any special shapes required by other industries.

Albany-based Blasch Precision Ceramics specializes in net shape ceramic solutions that offer protection from abrasion, high temperature and chemical corrosion applications. Utilizing its patented forming process and proprietary abrasion resistant materials, they create complex geometries otherwise unattainable using traditional manufacturing processes – helping engineers replace costly and hazardous fabricated metal components with pre-engineered ceramic shapes that reduce outage times while improving plant performance by increasing plant life span, cycle time efficiency, or improving efficiency overall.

Purebide® Reaction Bonded Silicon Carbide

Reaction Bonded Silicon Carbide (RBSC) ceramic is widely used for high temperature components like burner nozzles, radiant tubes and kiln furniture. RBSC boasts superior temperature resistance than quartz or polysilicon while remaining chemically stable; however it may be costly to produce due to requiring highly pure sintering aids and an elevated sintering temperature requirement.

Re-crystallization and reaction bonding have historically been the two primary methods for producing RBSC. Both processes involve high sintering temperatures of over 2200 degC which use up energy. Although various methods have been proposed to reduce cost by lowering sintering temperatures, none have yet provided commercially viable results.

At the University of Texas, to reduce costs associated with RBSC manufacturing, a new approach was devised that produces ceramic through indirect Selective Laser Sintering (SLS). After carbonizing in a vacuum furnace, this preform is ready for reactive infiltration with molten silicon for reactive infiltration. This approach significantly decreases manufacturing costs by eliminating the sintering step altogether and employing low sintering temperatures.

Morgan AM&T Purebide R was examined against two other ceramic materials – Ceralloy 146-1S and Wacker-Chemie SiC 100. Purebide R was observed to have lower MEF values, yet this did not suffice in improving its poor ballistic performance.

Poor ballistic performance of RBSC ceramic was traced back to its high concentration of un-reacted silicon metal present within it; research team was able to pinpoint this finding via x-ray analysis of ceramic samples.

X-ray images clearly demonstrated that ceramics had dense microstructures with few pores at both interface and interlayer levels, as seen through EDS imaging; reactive Si and residual Si phases could be identified in light gray and dark gray areas in EDS images, respectively. By comparison, both AME and Wacker ceramics featured much thinner and more porous interlayer and interface areas than their counterparts AME and Wacker had; due to having less resistance against abrasion and cracking.