SELECTED PROPERTIES OF SiC CERAMICS

The properties of SiC components may vary considerably depending on the respective production technology.
Pressure less sintered silicon carbide, SSiC, is the most suitable material for encapsulation of fuel and waste.

Property [Unit] RSiC1) NSiC2) SiSiC3) LPSiC4) SSiC5)
Open porosity Vol.-% 10 - 16 10 - 16 0 0 0
4-point bending strength MPa 80 - 120 120 - 200 200 - 400 500 - 600 400 - 500
Young’s Modulus GPa 220 200 350 380 420
Specific heat capacity at 30 – 1000 °C Jkg-1K-1 600 - 900 800 - 900 650 - 1300 600 600-1000
Thermal conductivity Wm-1K-1 18 - 20 14 - 16 100 - 150 90 120
Max. temperature of use °C 1600 1450 1380 1450 1760
Thermal shock resistance assessed good good good very good very good
Corrosion resistance assessed very good good poor at pH > 7 good excellent

1) RSiC: Recrystallized
2) NSiC: Nitride Bonded
3) SiSiC: Silicon Infiltrated, also named as Reaction Bonded
4) LPSiC: Liquid Phase Sintered
5) SSiC: Solid State Sintered (pressure less with boron as sintering aid)
For fuel cladding a substitution of boron as sintering aid is required.