Reaction Bonded Silicon Carbide - technical ceramic solutions

Reaction bonded silicon carbide (RB SiC) is an ideal material for near net forming processes such as pressing, injection molding and extrusion. Produced by infiltrating porous compacts with liquid silicon which results in reaction between carbon and silicon to form more SiC and hold initial particles together, creating near net forms with greater yields.

Reaction rates between amorphous carbon and liquid silicon depend upon its composition, morphology, degree of graphitization and distribution within a preform. As a result, residual carbon and pores will often remain visible in finished RB SiC materials.

Haute résistance

Reaction bonded silicon carbide’s exceptional strength makes it the ideal material for applications requiring resistance to impact, abrasion and erosion. Furthermore, its excellent tensile and compressive strengths make it resistant to cracking at high temperatures; additionally it is chemically inert making it suitable for use in potentially corrosive environments.

Reaction-bonded silicon carbide can be created through reactive melt infiltration (RMI). During this process, liquid silicon reacts with existing particles of silicon carbide and carbon to form dense impervious bodies containing high strength corrosion-resistant ceramic material that offers more economical alternatives to sintered silicon carbide.

RB SiC is an extremely hard engineering material with one of the highest hardness values. This gives it an outstanding wear and abrasion resistance and reduces friction between mating surfaces, helping reduce friction between them. Fiber reinforcement can further increase its tensile and compressive strengths.

Due to its ability to withstand high-temperatures, RB SiC is used in numerous applications ranging from nuclear reactors and gas turbines, as well as lightweight ballistic armor systems developed by Saint-Gobain Performance Ceramics & Refractories that protect against current and emerging threats. As it maintains structural integrity up to 1,400 degC temperatures, RB SiC plays an essential part in these systems.

High Corrosion Resistance

Silicon Carbide (SiC) boasts excellent corrosion resistance and does not degrade when exposed to high temperatures or chemicals that corrode it, such as acids or alkalis. Furthermore, SiC withstands strong mechanical loads without breaking or being deformed; chemical attacks by acids, alkalis or molten salts do not have an adverse impact. Furthermore, SiC offers impact resistance as well as having an extremely low coefficient of thermal expansion rate which protects it against sudden temperature changes that cause cracking or fractures in its life span.

Reaction-bonded silicon carbide (RB SiC) is an ideal material for near net forming processes like pressing, injection molding and extrusion because it withstands these operations with minimal dimensional change while meeting tolerances. Produced through impregnating composite precursors into porous preforms before high-temperature pyrolysis treatment involving liquid silicon reacting with the amorphous carbon particles to form bonds which increase density and strength of the final product.

Reaction bonded silicon carbide has proven its resistance to corrosion from combustion gases, coal slag and hot ash by developing an impervious oxide layer on its surface that absorbs and diffuses oxygen more slowly than free Si. Furthermore, RB SiC is less vulnerable to acid or alkali corrosion as well as possessing superior abrasion resistance properties.

Résistance aux températures élevées

Reaction bonded silicon carbide offers exceptional temperature stability and chemical resistance, making it an excellent material choice for mechanical seals, pumps and flow control chokes as well as wear components in mining industries. Furthermore, its low coefficient of thermal expansion enables it to withstand sudden changes in temperature without cracking under strain. RB SiC also boasts great wear resistance, making it suitable for applications requiring high temperature resistance such as tunnel kilns with its ability to resist sudden temperature swings without cracking up from sudden temperature shifts.

Reaction bonded silicon carbide (RB SiC) is produced by infiltrating porous carbon or graphite preforms with molten silicon and then controlling their reactivity with regard to carbon to limit any reactions between silicon and carbon, and to avoid any pore-clogging issues. Reaction bonded silicon carbide boasts outstanding dimensional tolerance even when produced through near net forming processes such as pressing, injection molding and extrusion.

Saint-Gobain Performance Ceramics & Refractories has developed an advanced process for manufacturing RB SiC materials suitable for high strength, high toughness applications such as composite armor systems. Their wide array of RB SiC products provides protection from current and emerging ballistic threats.

High Thermal Stability

Reaction bonded silicon carbide stands out among engineering ceramics with its unrivaled thermal stability, making it ideal for power devices operating at high temperatures as it can withstand intense heat without deforming or softening, saving energy while increasing output. Furthermore, its inherent thermal conductivity ensures energy conservation while increasing output.

Reaction bonded silicon carbide is produced by infiltrating porous carbon or graphite preforms with liquid silicon under controlled conditions to ensure complete carbon infiltration, without coarse particles remaining. The ceramic produced contains both original SiC grits from the preform as well as newly formed SiC produced during fabrication as well as residual silicon.

As part of the Reaction Bonding Process, infiltrating molten silicon reacts with both a-SiC and b-SiC to form dense covalent silicon carbide. The process can be enhanced further with carbon or boron carbide additives that promote silanization resulting in more a-SiC being created as silicon reacts with it, producing a denser and more homogenous structure than usual sintered silicon carbides.

Reaction bonded silicon carbide boasts superior wear, impact and corrosion resistance and can easily be formed into large or complex shapes, making it an attractive alternative to hot-press and pressureless sintered materials. React bonded silicon carbide may also provide reduced hardness levels while offering increased thermal shock resistance – perfect for applications where lower hardness levels may be suitable but additional thermal shock resistance may be essential.