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LAS/SiC vs SiC/SiC

Composite · grade comparison

LAS/SiC and SiC/SiC are both composite grades. SiC/SiC is the stronger of the two: tensile strength 300 MPa (43.5 ksi) against 260 MPa (37.7 ksi) for LAS/SiC, about 15% more. In exchange, LAS/SiC is the more ductile: elongation 0.7% versus 0.6% for SiC/SiC. SiC/SiC is stiffer (230 GPa vs 110 GPa) and SiC/SiC runs hotter in service (1,350°C vs 900°C continuous).

LAS/SiCChoose it when the part is bent, formed or impact-loaded.

SiC/SiCChoose it when strength drives the design, or when the part sees heat.

LAS/SiC vs SiC/SiC: properties

LAS/SiCSiC/SiC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

110 GPa16 Msi
230 GPa33.4 Msi

Shear Modulus

42 GPa6.1 Msi
95 GPa13.8 Msi

Bulk Modulus

70 GPa10.2 Msi
120 GPa17.4 Msi

Poisson's Ratio

0.22
0.18

Tensile Strength (Ultimate)

260 MPa37.7 ksi
300 MPa43.5 ksi

Elongation at Break

0.7%
0.6%

Compressive Strength

800 MPa116 ksi
600 MPa87 ksi

Compressive Modulus

110 GPa16 Msi
230 GPa33.4 Msi

Flexural Strength

400 MPa58 ksi
420 MPa60.9 ksi

Flexural Modulus

105 GPa15.2 Msi
210 GPa30.5 Msi

Shear Strength

45 MPa6.5 ksi
38 MPa5.5 ksi

Fracture Toughness (K_IC)

15 MPa·√m13.7 ksi·√in
25 MPa·√m22.8 ksi·√in

Physical

Density and transition temperatures.

Water Absorption (24 h)

0.3%
—

Same in both: Density 2.5 g/cm³0.09 lb/in³

Thermal

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

Thermal Conductivity

2.5 W/m·K1.4 BTU/hr·ft·°F
15 W/m·K8.7 BTU/hr·ft·°F

Specific Heat Capacity

900 J/kg·K0.21 BTU/lb·°F
700 J/kg·K0.17 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

3 µm/m·K1.7 µin/in·°F
4.3 µm/m·K2.4 µin/in·°F

Max Service Temperature (continuous)

900°C1,652 °F
1,350°C2,462 °F

Max Service Temperature (short-term)

1,200°C2,192 °F
1,600°C2,912 °F

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

Electrical

Conductivity and insulation.

Electrical Resistivity

1 Ω·m3.94×10⁷ µΩ·in
0.1 Ω·m3,937,000 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

78 / 100
88 / 100

UV / Weathering Resistance

98 / 100
100 / 100

Manufacturability

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

Machinability

8 / 100
4 / 100

Polishability

45 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

320 MJ/kg137,575 BTU/lb
1,500 MJ/kg644,885 BTU/lb

Embodied Carbon (primary production)

26 kg CO₂/kg
110 kg CO₂/kg

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

104 kN·m/kg
120 kN·m/kg

Specific Stiffness (E / density)

44 MN·m/kg
92 MN·m/kg

Thermal Diffusivity

1.1 mm²/s
8.6 mm²/s

Thermal Shock Resistance Index

2
5

Strength versus weight

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

1101001,000510Density (g/cm³)Yield strength (MPa) — log scale

Manufacturing and finishing

CapabilityLAS/SiCSiC/SiC
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

LAS/SiC vs SiC/SiC — frequently asked

Is SiC/SiC stronger than LAS/SiC?

Yes. SiC/SiC has a typical tensile strength of 300 MPa (43.5 ksi) against 260 MPa (37.7 ksi) for LAS/SiC — about 15% more.

Which is cheaper, LAS/SiC or SiC/SiC?

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 LAS/SiC over SiC/SiC?

Pick LAS/SiC when the part is bent, formed or impact-loaded. Pick SiC/SiC when strength drives the design, or when the part sees heat.

Ready to make it?

Upload a CAD file and FabDigit prices the part in LAS/SiC and SiC/SiC 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.