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Reaction Bonded Silicon Carbide
A precision silicon carbide material engineered for tight tolerances, near-zero porosity, and dimensional stability at high temperatures. Reaction bonded silicon carbide (RBSiC) is formed by infiltrating molten silicon into a porous silicon carbide green body. The resulting reaction creates additional SiC within the structure, producing a dense material with minimal dimensional change during firing.
For applications requiring exceptional resistance to aggressive sliding abrasion, RBSiC is an excellent choice when component geometries are relatively simple.
The Mechanism
How the Reaction Bond Forms
A green preform of SiC grain and free carbon is heated above silicon's melting point (1,414°C). Capillary action draws the molten silicon through the porous body, where it reacts with the carbon in place: Si + C → SiC. That newly formed SiC fills the remaining pore volume and fuses to the original grains, no shrinkage-driven densification required, which is why RBSiC holds tolerances that shrinkage-based ceramics can't match as-fired.
Because some free (unreacted) silicon typically remains in the final microstructure, RBSiC's service temperature ceiling is bound by silicon's melting point — a defining, testable material-science limit that distinguishes it from sintered SiC, which has no free-silicon phase at all.
Why is thermal conductivity so much higher than NBSiC?
At 45 W/m·K, roughly 2.5x NBSiC's 18 W/m·K, the dense, low-porosity structure conducts phonons (heat-carrying lattice vibrations) far more efficiently than a more porous ceramic.
Why Porosity Matters
Near-zero porosity resists chemical penetration and mechanical wear better than a more porous ceramic, without sacrificing dimensional stability.
Why SCP Sources This Grade
Reaction bonding uses a different process than our in-house nitride bonding. We partner with a vetted ceramic manufacturer so customers still get one quote and SCP-managed quality — without us claiming a process we don't run.
Material Properties
Reaction Bonded SiC at a Glance
Max Use Temp
2,480 - 2,516°F
(1,360 - 1,380°C)
Porosity
<0.1%
Thermal Conductivity
45 W/m·K
Sourcing
Vetted Partner Network
SCProbond™ Reaction Bonded Grade
SCProbond™ R
Precision Parts & Tight-Tolerance Components
Near-zero porosity and low thermal expansion give SCProbond™ R good thermal shock resistance and tight tolerances at extreme temperatures.