Precision Ceramics, a division of McGeoch Technology, is a company dedicated to the engineering of technical ceramics. From procurement and supply through to technical design and specialist machining, we offer a complete service.
Our reputation for quality and service is truly international with specialist ceramic components engineered by Precision Ceramics finding their way into an ever-widening array of worldwide applications in industries as diverse as aerospace, opto-electronics and nuclear power.
Features of Boron Nitride
A completely unique material, Boron Nitride solves problems that could not possibly be tackled with other compositions such as Al2O3 or SiC.
Boron Nitride fights off temperatures over 2,000°C and, depending on the grade, carries a dielectric strength of nearly 1000 volts/mil. Hot pressed in billet form, Boron Nitride can easily be machined into rods, bars, plates and even custom shapes.
The highly exceptional characteristics of Boron Nitride make it ideal for fixture or jig materials for sealing or brazing operations in induction, vacuum and atmosphere furnaces; for molten metal crucibles; heat sinks and high temperature insulators.
Boron Nitride - Grade M and M26
Solid Boron Nitride Grade M is a truly hydrophobic advanced ceramic. Composed of boron nitride and silica, it is completely resistant to moisture and has a MIL-I-10A grade of L542, a test requiring immersion in water for 48 hours prior to testing at elevated frequencies. Grade M is suitable for the most severe electrical applications. It is an excellent refractory material at temperatures up to 1400°C, and is unparalleled in resistance to thermal shock.
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Applications of Boron Nitride - Grade M and M26
Typical applications of Solid Boron Nitride Grade M and M26 include:
- High temperature electrical insulators and vacuum furnace supports which require electrical resistivity, high temperature strength, thermal shock resistance and low chemical resistivity
- Crucibles and containers for high purity molten metals
- Tools and refractories for glass forming which provide non-wetting, non-B2O3 containing contacts
- Radar components and antenna windows which require exacting electrical and thermal properties
- Spacers
Chemcial Composition of Boron Nitride - Grade M and M26
The chemical composition of Solid Boron Nitride Grade M and M26 is outline in the following table.
Table 1. Chemical composition of Boron Nitride - Grade M and M26
|
Chemical Composition
|
Grade M
|
Grade M26
|
|
Boron1
|
18-20.25%
|
26.5-28.7%
|
|
Nitrogen 1
|
22.5-25.5%
|
32.8-35%
|
|
Oxygen2
|
-
|
-
|
|
Calcium1
|
.01%3
|
.01%3
|
|
Silica (SiO2)1
|
60%
|
40%1
|
|
Other Inorganic1
|
.02%
|
.05%
|
|
Trace Metals
|
.05%
|
.05%
|
|
TOTAL
|
100%
|
100%
|
|
B2O3*
|
.2%
|
.2%
|
*B2O3 is given for clarification and is not part of the elemental analysis
1. Wet Chemistry - 2 LECO Oxygen - 3 Optical Emission Spectroscopy
Physical Properties of Boron Nitride - Grade M and M26
The physical properties of Solid Boron Nitride Grade M and M26 is outline in the following table.
Table 2. Physical properteis of Boron Nitride - Grade M and M26
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|
|
|
|
Percent BN:
|
|
|
|
Percent SiO2:
|
|
|
|
|
|
|
|
Volume Resistivity (ohm-cm) @ RT:
@150°C:
|
|
|
|
|
|
Dielectric Constant (@ IMHz) @RT:
microware frequency: @ RT, 8.8 GHz:
|
|
|
|
|
|
Dieletric Strength: volts/mil & (volts/mm)
|
|
Sample thickness: 10 mil.
Tested up to 25kV) 25 mil
|
1670 (65748)
>1000 (>39370)
|
1690 (66535)
>1000 (39370)
|
|
Dissipation Factor (Loss tangent)
|
|
@RT @ 1 MHz
@150°C @ 1 MHz
@RT @ 8.8 GHz
|
0016 .0035
.0017 .0055
.0011 .0005
|
.0017 .0061
.0094 .0062
.0039 .0006
|
|
Loss Factor
@RT @ 1 MHz
@150°C @ 1 MHz
@RT @ 8.8 GHz
|
.0067 .0140
.0077 .0230
.0042 .0020
|
.0076 .0230
.0440 .0250
.0150 .0260
|
|
Surface Resistivity (ohms/ )@ RT
@150°C
|
|
|
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This information has been sourced, reviewed and adapted from materials provided by Precision Ceramics.
For more information on this source, please visit Precision Ceramics.