FabDigit

Sialon vs Silicon Nitride and 2 more: properties

SialonSilicon NitrideBoron NitrideAlN

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

288 GPa41.8 Msi
310 GPa45 Msi
45 GPa6.5 Msi
320 GPa46.4 Msi

Shear Modulus

113 GPa16.4 Msi
122 GPa17.7 Msi
18 GPa2.6 Msi
130 GPa18.9 Msi

Bulk Modulus

205 GPa29.7 Msi
222 GPa32.2 Msi
36 GPa5.2 Msi
200 GPa29 Msi

Poisson's Ratio

0.27
0.27
0.2
0.24

Tensile Strength (Ultimate)

350 MPa50.8 ksi
450 MPa65.3 ksi
35 MPa5.1 ksi
200 MPa29 ksi

Compressive Strength

3,500 MPa508 ksi
3,000 MPa435 ksi
90 MPa13.1 ksi
2,100 MPa305 ksi

Flexural Strength

945 MPa137 ksi
800 MPa116 ksi
55 MPa8 ksi
330 MPa47.9 ksi

Fracture Toughness (K_IC)

7.7 MPa·√m7 ksi·√in
6.5 MPa·√m5.9 ksi·√in
1 MPa·√m0.91 ksi·√in
2.7 MPa·√m2.5 ksi·√in

Hardness, Vickers

1,550 HV
1,500 HV
1,100 HV

Hardness, Knoop

1,450 HK
1,500 HK
1,200 HK

Hardness, Mohs

9
9
2
7.5

Elongation at Break

0%

Physical

Density and transition temperatures.

Density

3.25 g/cm³0.12 lb/in³
3.22 g/cm³0.12 lb/in³
2 g/cm³0.07 lb/in³
3.26 g/cm³0.12 lb/in³

Melting Point (Solidus)

1,800°C3,272 °F
1,900°C3,452 °F
2,973°C5,383 °F
2,200°C3,992 °F

Porosity

0.3%
0.5%
8%
0.2%

Light Transmission

0%

Refractive Index

1.75
2.15

Thermal

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

Thermal Conductivity

21 W/m·K12.1 BTU/hr·ft·°F
25 W/m·K14.4 BTU/hr·ft·°F
33 W/m·K19.1 BTU/hr·ft·°F
180 W/m·K104 BTU/hr·ft·°F

Specific Heat Capacity

690 J/kg·K0.16 BTU/lb·°F
700 J/kg·K0.17 BTU/lb·°F
800 J/kg·K0.19 BTU/lb·°F
740 J/kg·K0.18 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

3 µm/m·K1.7 µin/in·°F
3.2 µm/m·K1.8 µin/in·°F
2 µm/m·K1.1 µin/in·°F
4.4 µm/m·K2.4 µin/in·°F

Max Service Temperature (continuous)

1,200°C2,192 °F
1,200°C2,192 °F
1,000°C1,832 °F
900°C1,652 °F

Min Service Temperature

-200°C-328 °F
-269°C-452 °F
-200°C-328 °F
-200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in
1×10¹² Ω·m3.94×10¹⁹ µΩ·in
1×10¹³ Ω·m3.94×10²⁰ µΩ·in
1×10¹² Ω·m3.94×10¹⁹ µΩ·in

Dielectric Strength

15 kV/mm381 V/mil
15 kV/mm381 V/mil
40 kV/mm1,016 V/mil
17 kV/mm432 V/mil

Dielectric Constant (1 MHz)

7.9
8
4.1
8.8

Dissipation Factor (1 MHz)

0.002
0.001
4×10⁻⁴
5×10⁻⁴

Volume Resistivity

1×10¹³ Ω·cm
1×10¹⁴ Ω·cm
1×10¹⁵ Ω·cm
1×10¹⁴ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

90 / 100
92 / 100
70 / 100
85 / 100

Manufacturability

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

Machinability

4 / 100
5 / 100
85 / 100
5 / 100

Polishability

85 / 100
92 / 100
25 / 100
85 / 100

Sintering / Firing Temperature

1,750°C3,182 °F
1,750°C3,182 °F
1,800°C3,272 °F
1,800°C3,272 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

230 MJ/kg98,882 BTU/lb
170 MJ/kg73,087 BTU/lb
250 MJ/kg107,481 BTU/lb
280 MJ/kg120,378 BTU/lb

Embodied Carbon (primary production)

14 kg CO₂/kg
12 kg CO₂/kg
20 kg CO₂/kg
22 kg CO₂/kg

Embodied Water

250 L/kg30 gal/lb
220 L/kg26.4 gal/lb
120 L/kg14.4 gal/lb
300 L/kg35.9 gal/lb

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

108 kN·m/kg
140 kN·m/kg
18 kN·m/kg
61 kN·m/kg

Specific Stiffness (E / density)

88.6 MN·m/kg
96.3 MN·m/kg
22.5 MN·m/kg
98.2 MN·m/kg

Thermal Diffusivity

9.4 mm²/s
11.1 mm²/s
20.6 mm²/s
74.6 mm²/s

Thermal Shock Resistance Index

9
11
13
26

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 scaleSilicon NitrideBoron Nitride

Manufacturing and finishing

CapabilitySialonSilicon NitrideBoron NitrideAlN
Default condition
Relative cost$$$$ High$$$$ High$$$$ High$$$$ High
Min. machined wall
Best machined surface

Ready to make it?

Upload a CAD file and FabDigit prices the part in Sialon and Silicon Nitride 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.