Reaction Bonded SiC – Superior Durability for Harsh Conditions
Silicon Carbide (SiC) is an ideal ceramic material for harsh conditions, offering high strength, temperature stability and thermal shock resistance.
RB SiC is produced by infiltrating porous carbon-based preforms with liquid or vapour silicon. The resultant ceramic features an interconnected network of SiC grains held together by residual silicon.
Superior Durability
Reaction Bonded Silicon Carbide stands up well against high temperatures, corrosion and wear. As one of the hardest materials available today with excellent thermal stability, ReactBonded silicon carbide makes an excellent material choice for pump parts, mechanical seals and other demanding uses.
Traditional reaction bonded silicon carbide ceramics make the production of C/SiC preforms with an engineering density close to theoretical density challenging, depending on factors such as carbon morphology and distribution in the preform as well as impregnation step counts and duration. Residual silicon content of final ceramics also depends on this factor as well as degree of graphitization and size of pores.
our innovative reaction technology facilitates the production of dense, porous RB SiC ceramics using an innovative process involving multiple cycles of resin impregnation and pyrolysis followed by infiltration of liquid silicon into a preform. The final ceramics exhibit superior engineering densities, dimensional stability and improved durability.
High Resistance to Corrosion
Reaction Bonded SiC is known for its superior strength and thermal conductivity, making it resistant to chemical corrosion in harsh environments. Furthermore, its resistance to oxidation, radiation and wear provide lasting performance in any condition.
Sintered Silicon Carbide (SSiC) and Reaction Bonded SiC are two ceramic materials with multiple applications. SSiC is created by pressing and sintering silicon carbide powder; while RBSiC offers greater chemical resistance.
Reaction Bonded SiC is produced by infiltrating formed parts of silicon carbide and carbon with metallic silicon in order to bond the grains of silicon carbide and fill any remaining pore spaces, creating a highly wear-, oxidation, and thermal shock-resistant material with low thermal mass kiln supports made of RBSiC that results in energy savings as well as lower calcination costs; we currently manufactures beams, posts, setters, burner nozzles and rolls out of Reaction Bonded SiC.
High Strength
Silicon Carbide ceramic is one of the hardest and strongest ceramics. It retains its hardness even at high temperatures, with excellent abrasion and erosion resistance and half the weight of steel; furthermore, it boasts superior thermal conductivity than most other ceramics.
Reverse Microinjection involves infiltrating liquid Si with capillary action into a porous C/SiC preform containing carbon to produce secondary SiC growth inside its pores; however, due to 5-40 vol% residual carbon present, its density, melting point, Young’s modulus and thermal conductivity differ significantly from that of primary silicon carbide.
To reduce residual carbon content, we impregnated C/SiC porous preforms with composite carbon sources through impregnation. The graphitized mesocarbon microbeads and amorphous carbon of our composite precursor increased primary silicon carbide production while multiphase carbon helped prevent liquid Si from reacting with carbon, thus avoiding any pore-clogging issues and producing high performance RB-SiC products.
Versatile Applications
RB SiC ceramics are used in demanding applications in harsh environments such as high temperature and corrosion, offering strength, thermal shock resistance and chemical corrosion resistance – an ideal combination for many industrial uses.
Traditional RB-SiC is typically manufactured by sintering coarse and medium grain SiC powder with 5 to 15 weight percent aluminosilicate binder in air at temperatures above 300 oF (149 oC), softening at higher application temperatures due to softening silicate binder, producing ceramics that exhibit lower strengths and corrosion resistance than non-oxide bonded SiC materials.
RB-SiC offers lower flexural strengths and Young’s moduli than pressureless sintered SiC (HPSIC). To create this material, a phenolic resin impregnation system allows for the creation of preforms with controlled carbon content which are then infiltrated with liquid silicon via infiltration at high temperature soaking times; various microstructures can then be achieved through changing soak time/temperature combinations; during which carbon source reactions consume carbon sources, while any residual silicon is consumed through infiltration at high temperature through infiltration soaking times/temperature variations to form preforms with controlled carbon content soaked before infiltrated liquid silicon infiltration soaking times/temperature combinations allow different microstructures to emerge.
