Boron nitride machinable ceramic
Boron nitride is an advanced synthetic ceramic material available as a powder, solid, liquid or aerosol.
It has exceptional temperature resistance, dielectric strength and thermal conductivity. Thanks to these various properties, boron nitride is an easily machinable material.
To obtain sintered boron nitride, the boron nitride powder is pressed at a very high temperature.
The 2 methods used are :
- uniaxial hot pressing (HP)
- hot isostatic pressing (HIP).
Boron nitride can be compared to graphite thanks to these lubrication capacities and its good thermal conduction, although it is white in colour and has very good electrical insulation capabilities. In its solid form, boron nitride can easily be machined in virtually any form. Boron nitride is resistant to temperatures above 2000°C in inert and reducing atmospheres.
Plus, it isn't wetted by most molten metals and slags and can therefore be used as a container for most molten metals, including aluminium, sodium, iron, steel, silicon, boron and copper.
Notable properties
- High thermal conductivity
- Low thermal expansion
- Excellent dielectric resistance
- Chemical inertia
- Microwave transparency
- Easily machinable
Applications
- Protection and sheathing for thermocouples and measuring probes
- Protection for casting tools
- Electrical insulation at very high temperatures
- Smelting and sintering crucibles
- Resistance support
- Solar and photovoltaic industry
- Furnace structures: tubes and insulation sleeves
- Soldering and brazing: nozzles, brazing supports
- PVD installations: masking supports, coating supports
Standard products
-
Final®BN - Boron nitride with binder
-
Final®BN HP - High-purity boron nitride without binder
-
Final®BN HD2 - Boron nitride with greater mechanical resistance
|
Unit |
Final®BN |
Final®BN HP |
Final®BN HD2 |
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|
Composition |
hBN |
hBN |
hBN |
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|
Structure |
anisotropic |
anisotropic |
anisotropic |
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|
Purity |
% BN |
~91.6 - 96.1 |
~99.3 |
~98.9 |
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|
Binder |
Calcium borate and boron oxide |
- |
Boron oxide |
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|
Volumic mass |
g/cm³ |
2 |
1.9 |
2.06 |
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|
Max. temp. in oxidising atmospheres |
°C |
850 |
850 |
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|
Max. temp. in inert atmospheres |
°C |
1150 |
2000 |
1600 |
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|
Direction of application of pressure |
ǁ |
^ |
ǁ |
^ |
ǁ |
^ |
|
|
Thermal conductivity at 25°C |
W/mK |
27 |
29 |
78 |
130 |
92.7 |
57.2 |
|
Thermal dilatation coefficient |
800-1200°C |
800-1200°C |
1200-1600°C |
1200-1600°C |
20-1500°C |
20-1500°C |
|
|
10-6K-1 |
1.5 |
0.9 |
0.9 |
0.3 |
7.54 |
2.12 |
|
|
Flexural strength at 25°C |
MPa |
59 |
45 |
22 |
21 |
25.5 |
47.9 |
|
Young module |
GPa |
40 |
60 |
17 |
71 |
35 |
50 |
|
Compressive strength |
MPa |
30 |
48 |
18 |
23 |
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|
Electrical resistivity at 20 °C |
Ohm.cm |
>1014 |
>1015 |
> 1014 |
> 1015 |
>1013 |
>1013 |
|
Electrical rigidity |
kV/mm |
>10 |
79 |
>50 |
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|
Applications |
Vacuum furnace insulator, high-temperature insulator |
Vacuum furnace insulator, high-temperature insulator, atomising nozzle, electrical insulation |
Vacuum furnace insulator, high-temperature insulator |
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We can offer various grades of boron nitride whose compositions contain other ceramics such as SiC, ZrO2, SiO2, AlN. If a particular boron nitride composition is required for specific applications, please contact us.
We can also provide boron nitrides on request from Saint-Gobain, COMBAT®products : grade A, HP, AX05, M, M26 and ZSBN.
Specific boron nitride products
|
Unité |
Final®BN P |
Final®BN C |
Final®BN I |
Final®BN Z20 |
Final®BN Z40 |
Final®BN Z40D |
Final®BN S |
Final®BN A |
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|
Composition |
|
hBN |
hBN |
hBN |
hBN+SiC+ZrO2 |
hBN+SiC+ZrO2 |
hBN+SiC+ZrO2 |
hBN+SiO2 |
hBN+AlN |
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|
Structure |
|
anisotropic |
anisotropic |
isotropic |
anisotropic |
anisotropic |
anisotropic |
anisotropic |
anisotropic |
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|
Binder |
|
- |
Calcium borate |
- |
- |
Boron oxide |
Boron oxide |
- |
Boron oxide + calcium borate |
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|
Volumic mass |
g/cm³ |
1.9 |
2.0 |
2.0 |
2.4 |
2.9 |
2.9 |
2.2 |
2.5 |
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|
Max. temp. in oxidising atmospheres |
°C |
900 |
900 |
900 |
900 |
900 |
900 |
900 |
900 |
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|
Max. temp. in inert atmospheres |
°C |
2300 |
1600 |
2300 |
1800 |
1800 |
1800 |
1500 |
1600 |
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|
Direction of application of pressure |
ǁ |
^ |
ǁ |
^ |
ǁ |
^ |
ǁ |
^ |
ǁ |
^ |
ǁ |
^ |
ǁ |
^ |
ǁ |
^ |
|
|
Thermal conductivity at 20˚C |
W/mK |
20 |
30 |
33 |
35 |
25 |
28 |
45 |
28 |
38 |
24 |
34 |
10 |
30 |
30 |
40 |
|
|
Thermal dilatation coefficient 20-1500°C |
10-6K-1 |
1.0 |
0.5 |
4.0 |
3.0 |
3.0 |
4.5 |
3.0 |
8.0 |
4.0 |
6.0 |
4.0 |
3.0 |
0.1 |
5.6 |
5.4 |
|
|
Flexural strength at 25°C |
MPa |
15 |
18 |
35 |
40 |
30 |
40 |
70 |
80 |
120 |
107 |
144 |
35 |
65 |
80 |
105 |
|
|
Young module |
GPa |
11 |
14 |
25 |
30 |
23 |
20 |
35 |
30 |
45 |
50 |
71 |
75 |
85 |
40 |
60 |
|
|
Compressive strength |
MPa |
27 |
22 |
60 |
52 |
45 |
140 |
60 |
240 |
120 |
280 |
160 |
130 |
50 |
190 |
185 |
|
|
Electrical resistivity at 20°C |
Ohm.cm |
>1012 |
>1012 |
>1012 |
>1012 |
>1012 |
- |
>1014 |
>1015 |
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|
Applications |
|
Temp. > 1600°C e.g. furnace structures |
Max. temp. ~1600°C e.g. PVD, furnace structures |
Very high-temperature processes > 1800°C e.g. capillary tubes, thermocouples |
Temp. < 1800°C e.g. casting nozzles, molten metal crucibles |
Temp. < 1800°C e.g. casting nozzles, molten metal crucibles |
Temp. < 1800°C e.g. special applications, steel industry |
Max. temp. 1500°C e.g. PVD |
Glass industry |
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