Non-oxide Ceramics – Silicon Carbide (SiSiC/SSiC)

A Ceramic Material Hard as Diamond

Silicon carbide behaves almost like a diamond. It is not only the lightest, but also the hardest ceramic material and has excellent thermal conductivity, low thermal expansion and is very resistant to acids and lyes.

Nichtoxidkeramik – Siliziumkarbid

Worth knowing:

Properties of Silicon Carbide (SSiC / SiSiC)

  • Low density (3.07 to 3.15 g/cm3)
  • High hardness (HV10 ≥ 2,200 GPa)
  • High Young’s modulus (380 to 430 MPa)
  • High thermal conductivity (120 to 200 W/mK)
  • Low coefficient of linear expansion
    (3.6 to 4.1x10-6/K at 20 to 400°C)
  • Maximum operating temperature of SSiC under inert gas: 1,800°C
  • Excellent thermal shock resistance of SiSiC: ΔT 1,100 K
  • Erodible
  • Corrosion and wear resistant even at high temperatures
  • Toxicologically safe
  • Good gliding properties

With silicon carbide ceramics the material properties remain constant up to temperatures above 1,400°C. The high Young’s modulus > 400 GPa ensures excellent dimensional stability. These material properties make silicon carbide predestined for use as a construction material. Silicon carbide masters corrosion, abrasion and erosion as skillfully as it stands up to frictional wear. Components are used in chemical plants, mills, expanders and extruders or as nozzles, for example.

“The variants SSiC (sintered silicon carbide) and SiSiC (silicon infiltrated silicon carbide) have established themselves. The latter is particularly suitable for the production of complex large-volume components.”

Silicon carbide is toxicologically safe and can be used in the food industry. Another typical application for silicon carbide components is dynamic sealing technology using friction bearings and mechanical seals, for instance in pumps and drive systems. Compared to metals, silicon carbide enables highly economical solutions with longer tool life when used with aggressive, high-temperature media. Silicon carbide ceramics are also ideal for use in demanding conditions in ballistics, chemical production, energy technology, paper manufacturing and as pipe system components.