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Cr3C2 vs RBSiC/SiSiC

Ceramic · grade comparison

Cr3C2 and RBSiC/SiSiC are both ceramic grades. RBSiC/SiSiC is harder — 2,300 HV against 1,400 HV for Cr3C2 — which matters for wear surfaces and threads. RBSiC/SiSiC is lighter (3.05 g/cm³ vs 6.68 g/cm³ for Cr3C2) and RBSiC/SiSiC runs hotter in service (1,350°C vs 1,000°C continuous).

RBSiC/SiSiCChoose it when surface hardness matters, or when weight is the constraint.

Cr3C2 vs RBSiC/SiSiC: properties

Cr3C2RBSiC/SiSiC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

373 GPa54.1 Msi
390 GPa56.6 Msi

Shear Modulus

145 GPa21 Msi
167 GPa24.2 Msi

Bulk Modulus

282 GPa40.9 Msi
191 GPa27.7 Msi

Poisson's Ratio

0.28
0.17

Compressive Strength

1,200 MPa174 ksi
2,500 MPa363 ksi

Flexural Strength

400 MPa58 ksi
320 MPa46.4 ksi

Shear Strength

300 MPa43.5 ksi
180 MPa26.1 ksi

Fracture Toughness (K_IC)

4 MPa·√m3.6 ksi·√in
3.7 MPa·√m3.4 ksi·√in

Hardness, Vickers

1,400 HV
2,300 HV

Hardness, Knoop

1,300 HK
2,200 HK

Hardness, Mohs

9
9.3

Same in both: Tensile Strength (Ultimate) 200 MPa29 ksi · Elongation at Break 0%

Physical

Density and transition temperatures.

Density

6.68 g/cm³0.24 lb/in³
3.05 g/cm³0.11 lb/in³

Melting Point (Solidus)

1,810°C3,290 °F
1,410°C2,570 °F

Porosity

2%
0.2%

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

19 W/m·K11 BTU/hr·ft·°F
130 W/m·K75.1 BTU/hr·ft·°F

Specific Heat Capacity

500 J/kg·K0.12 BTU/lb·°F
700 J/kg·K0.17 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

10.3 µm/m·K5.7 µin/in·°F
4.3 µm/m·K2.4 µin/in·°F

Max Service Temperature (continuous)

1,000°C1,832 °F
1,350°C2,462 °F

Same in both: Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

7.5×10⁻⁷ Ω·m29.5 µΩ·in
0.001 Ω·m39,370 µΩ·in

Volume Resistivity

7.5×10⁻⁵ Ω·cm
0.1 Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

85 / 100
88 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Polishability

75 / 100
80 / 100

Sintering / Firing Temperature

1,600°C2,912 °F
1,550°C2,822 °F

Same in both: Machinability 4 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

95 MJ/kg40,843 BTU/lb
105 MJ/kg45,142 BTU/lb

Embodied Water

—
90 L/kg10.8 gal/lb

Same in both: Embodied Carbon (primary production) 7.5 kg CO₂/kg · Typical Recycled Content 5%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

30 kN·m/kg
66 kN·m/kg

Specific Stiffness (E / density)

55.8 MN·m/kg
127.9 MN·m/kg

Thermal Diffusivity

5.7 mm²/s
60.9 mm²/s

Thermal Shock Resistance Index

1
16

Strength versus weight

Yield strength against density for every ceramic grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

501002005001,000234567Density (g/cm³)Yield strength (MPa) — log scale

Manufacturing and finishing

CapabilityCr3C2RBSiC/SiSiC
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Cr3C2 vs RBSiC/SiSiC — frequently asked

What is the difference between Cr3C2 and RBSiC/SiSiC?

Cr3C2 and RBSiC/SiSiC are both ceramic grades. RBSiC/SiSiC is harder — 2,300 HV against 1,400 HV for Cr3C2 — which matters for wear surfaces and threads. RBSiC/SiSiC is lighter (3.05 g/cm³ vs 6.68 g/cm³ for Cr3C2) and RBSiC/SiSiC runs hotter in service (1,350°C vs 1,000°C continuous).

Which is cheaper, Cr3C2 or RBSiC/SiSiC?

Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.

When should I choose Cr3C2 over RBSiC/SiSiC?

Pick RBSiC/SiSiC when surface hardness matters, or when weight is the constraint.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Cr3C2 and RBSiC/SiSiC side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.