Silicon Carbide
Silicon carbide (SiC, carborundum) is a synthetic non-oxide ceramic with Mohs hardness 9.2 — second only to diamond and boron carbide — and service to 1450°C in air. Produced by Acheson carbothermal reduction of quartz sand and petroleum coke. Four grade families cover bulk abrasive/refractory, precision ceramic micropowder, and high-purity sintered structural ceramic.
Key Properties at a Glance
| Product Range | Black SiC sand & refractory / Green SiC sand / SiC micropowder / Sintering-grade (RBSC, SSiC, R-SiC) |
|---|---|
| Hardness | Mohs 9.2 – 9.3 / Knoop ~2480–2500 HK |
| Service Temperature | ≤1450°C in air; ≤1650°C in inert/reducing atmosphere |
| Crystal System | α-SiC hexagonal (industrial trade) / β-SiC cubic (specialty) |
| SiC Purity Range | ≥80% (refractory aggregate) → ≥99.5% (semiconductor / ballistic / IGBT substrate) |
| Particle Size Range | F14–F220 sand / P12–P2500 P-grit / JIS240–JIS10000 + F230–F2000 micropowder / W63–W0.5 sintering / 0–3 mm refractory |
| Standards | GB/T 2481.2 / ISO 8486-1 & 8486-2 / JIS R6001-1998 / FEPA 42-GB-1984 / FEPA 43-1984 (P-grit) |
Range shown is category-wide; refer to individual grade COA for precise specs.
Featured Grades
Black Silicon Carbide (C / CP / Refractory)
CAS 409-21-2
Black silicon carbide is synthesized from quartz sand (SiO₂) and petroleum coke (C) in an Acheson electric resistance furnace at >1800°C. SiC content ≥98.5%, with a slightly higher Fe₂O₃ and free-C tail than the green grade — the difference that puts black SiC at a 15–25% price discount and makes it the workhorse abrasive and refractory raw material across coated abrasives, foundry blast media, ceramic-bonded grinding wheels, kiln-furniture batters, and steelmaking deoxidizer. Supplied in coarse particle-size sand (F14–F220, ISO 8486-1 / GB/T 2481.2), in P-grit for coated-abrasive papers and belts (P12–P2500), and in refractory aggregates 0–1 mm / 1–3 mm at graded SiC purity 80% to 98%.
Green Silicon Carbide (GC)
CAS 409-21-2
Green silicon carbide is the higher-purity grade synthesized from selected high-purity quartz and petroleum coke under stricter furnace control, with sodium chloride added to the charge as a re-crystallization promoter — the result is α-SiC with characteristic green colour, SiC content ≥99.0%, and hardness slightly higher than black SiC. Green SiC is the abrasive of choice when iron contamination matters (semiconductor wire-saw slurry, optical glass, hard alloy, jade and gemstone polishing) and for premium vitrified-bonded grinding wheels on hardened tool steel, carbide, and ceramic substrates. Supplied in F14–F220 sand and F230–F2000 micropowder.
Silicon Carbide Micropowder (Overflow / Siphon / Air-Classified)
CAS 409-21-2
SiC micropowder is the sub-micron-to-tens-of-microns fraction produced by milling crushed SiC and classifying through two complementary techniques: water-sedimentation (overflow / siphon) for JIS240–JIS10000 grades following the principle of differential settling velocity, and air-classification for FEPA F230–F2000 grades following Stokes-flow particle separation. Both routes are governed by ISO 8486-2 and JIS R6001-1998. Particle median (D50) ranges from 57 μm (JIS240) down to 0.5 μm (JIS10000) with tightly controlled D3/D94 cuts. SiC purity ≥99.0%, specific gravity ≥3.16. The downstream applications are radically different from coarse SiC sand — micropowder serves coatings, ceramic forming, precision polishing, and high-tech filter applications.