Boron nitride machinable ceramic

BN - 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

Composition

hBN

hBN

hBN

Structure

anisotropic

anisotropic

anisotropic

Purity

% BN

~91.6 - 96.1

~99.3

~98.9

Binder

Calcium borate and boron oxide

-

Boron oxide

Volumic mass

g/cm³

2

1.9

2.06

Max. temp. in oxidising atmospheres

°C

850

850

Max. temp. in inert atmospheres

°C

1150

2000

1600

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

Electrical resistivity at 20 °C

Ohm.cm

>1014

>1015

> 1014

> 1015

>1013

>1013

Electrical rigidity

kV/mm

>10

79

>50

Applications

Vacuum furnace insulator, high-temperature insulator

Vacuum furnace insulator, high-temperature insulator, atomising nozzle, electrical insulation

Vacuum furnace insulator, high-temperature insulator

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

FinaBN I

Final®BN Z20

Final®BN Z40

Final®BN Z40D

Final®BN S

Final®BN A

Composition

 

hBN

hBN

hBN

hBN+SiC+ZrO2

hBN+SiC+ZrO2

hBN+SiC+ZrO2

hBN+SiO2

hBN+AlN

Structure

 

anisotropic

anisotropic

isotropic

anisotropic

anisotropic

anisotropic

anisotropic

anisotropic

 

Binder

 

-

Calcium borate

-

-

Boron oxide

Boron oxide

-

Boron oxide + calcium borate

Volumic mass

g/cm³

1.9

2.0

2.0

2.4

2.9

2.9

2.2

2.5

Max. temp. in oxidising atmospheres

°C

900

900

900

900

900

900

900

1100

Max. temp. in inert atmospheres

°C

2300

1600

2300

1800

1800

1800

1500

1600

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

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

Boron Nitride BN (239.65k)

Technical data sheet


Machinable technical ceramics (873.92k)

Machinable technical ceramics data sheet.