会社のニュース SSiC vs Recrystallized SiC (RSiC): Strength, Porosity and Performance

The core difference is porosity

• RSiC: ~15% porosity
• SSiC: ~0 (near fully dense)

Porosity determines strength, corrosion resistance, and lifetime

• RSiC = large grains + open pores
• SSiC = fine grains + dense structure

Porosity acts as:

• crack initiation sites
• diffusion channels
• stress concentrators

High porosity leads to:

• Lower mechanical strength (load cannot be transferred effectively)
• Faster corrosion (gas/liquid penetration)
• Accelerated creep deformation
• Reduced service life

Porosity is not just a structure feature—it is a failure origin

• SSiC ≈ 3–4* strength of RSiC
• Difference increases at high temperature

At elevated temperatures, porous structures degrade faster due to grain boundary weakening.

RSiC:

• porous → stress concentration
• grain boundary sliding
• deformation under load

SSiC:

• dense structure
• higher modulus (~420–430 GPa)
• better creep resistance

Creep deformation is strongly controlled by density and grain bonding

Suitable for:

• lightweight structures
• low load applications
• thermal shock environments

Not suitable for:

• long-span beams
• high mechanical load

Suitable for:

• kiln rollers / beams
• lithium battery furnaces
• chemical environments

Especially critical for:

• long-term operation (>1000 h)
• high temperature (>1400°C)

Use SSiC if:

✔ High load
✔ Long span
✔ Corrosive atmosphere
✔ Long service life required

Use RSiC if:

✔ Lightweight is priority
✔ Mechanical load is low

RSiC → lightweight but limited by porosity
SSiC → dense structure → stable performance

For demanding applications, SSiC is the safer engineering choice