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AlN vs CBN

Ceramic · grade comparison

AlN and CBN are both ceramic grades. AlN is lighter (3.26 g/cm³ vs 3.48 g/cm³ for CBN) and CBN is stiffer (860 GPa vs 320 GPa).

AlNChoose it when weight is the constraint.

CBNChoose it when the part sees heat.

AlN vs CBN: properties

AlNCBN

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

320 GPa46.4 Msi
860 GPa125 Msi

Shear Modulus

130 GPa18.9 Msi
405 GPa58.7 Msi

Bulk Modulus

200 GPa29 Msi
400 GPa58 Msi

Poisson's Ratio

0.24
0.14

Tensile Strength (Ultimate)

200 MPa29 ksi
—

Compressive Strength

2,100 MPa305 ksi
5,000 MPa725 ksi

Flexural Strength

330 MPa47.9 ksi
—

Fracture Toughness (K_IC)

2.7 MPa·√m2.5 ksi·√in
3 MPa·√m2.7 ksi·√in

Hardness, Vickers

1,100 HV
—

Hardness, Knoop

1,200 HK
4,700 HK

Hardness, Mohs

7.5
9.9

Physical

Density and transition temperatures.

Density

3.26 g/cm³0.12 lb/in³
3.48 g/cm³0.13 lb/in³

Melting Point (Solidus)

2,200°C3,992 °F
2,973°C5,383 °F

Refractive Index

2.15
2.117

Porosity

0.2%
0%

Thermal

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

Thermal Conductivity

180 W/m·K104 BTU/hr·ft·°F
740 W/m·K428 BTU/hr·ft·°F

Specific Heat Capacity

740 J/kg·K0.18 BTU/lb·°F
506 J/kg·K0.12 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

4.4 µm/m·K2.4 µin/in·°F
4.8 µm/m·K2.7 µin/in·°F

Max Service Temperature (continuous)

900°C1,652 °F
1,200°C2,192 °F

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

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹² Ω·m3.94×10¹⁹ µΩ·in
1×10¹⁰ Ω·m3.94×10¹⁷ µΩ·in

Dielectric Strength

17 kV/mm432 V/mil
—

Dielectric Constant (1 MHz)

8.8
7.1

Dissipation Factor (1 MHz)

5×10⁻⁴
—

Volume Resistivity

1×10¹⁴ Ω·cm
1×10¹² Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

85 / 100
93 / 100

Manufacturability

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

Machinability

5 / 100
2 / 100

Polishability

85 / 100
92 / 100

Sintering / Firing Temperature

1,800°C3,272 °F
1,500°C2,732 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

280 MJ/kg120,378 BTU/lb
900 MJ/kg386,931 BTU/lb

Embodied Carbon (primary production)

22 kg CO₂/kg
55 kg CO₂/kg

Embodied Water

300 L/kg35.9 gal/lb
—

Typical Recycled Content

0%
5%

Common Calculations

Ratios derived from the values above.

Specific Stiffness (E / density)

98.2 MN·m/kg
247.1 MN·m/kg

Thermal Diffusivity

74.6 mm²/s
420.2 mm²/s

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

CapabilityAlNCBN
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

AlN vs CBN — frequently asked

What is the difference between AlN and CBN?

AlN and CBN are both ceramic grades. AlN is lighter (3.26 g/cm³ vs 3.48 g/cm³ for CBN) and CBN is stiffer (860 GPa vs 320 GPa).

Which is cheaper, AlN or CBN?

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 AlN over CBN?

Pick AlN when weight is the constraint. Pick CBN when the part sees heat.

Ready to make it?

Upload a CAD file and FabDigit prices the part in AlN and CBN 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.