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Boron
Nitride (BN) |
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Hexagonal
boron nitride ( white graphite ) is one kind of loose, lubricious
and hygrometric white powder. Its theoretical density is 2.27/cm3, Mosh
hardness is 2. Its mechanical strength is lower, but higher than the
graphite¡¯s ( seeing the table 1 ) . It has not the exact melting point ,
but sublimates at 3000 ℃ in 0.1Mpa nitrogen gas . The highest using
temperature is 2800 ℃ in nitrogen or argon gas ,but below 1000
℃ in oxygen.
It
has lower thermal expansion coefficient and higher thermal conductive
rate , so its heat-resisting shaking ability is fine . The loop time
from 1200 ℃
to 20 ℃ is more than one hundred and the BN has not been destoried
.
Boron nitride
belongs to hexagonal crystal system , its crystal structure is similar to
graphite , so it is also called white graphite . B and N atom arrange to
six-angle ring network alternately. Their structure are showed in Fig. 3.
The atoms in layer bond each other covalently and strongly, but the atoms
between layers bond with molecular bond, so it is weak and ease to break.
The atom space of B-N in each layer is 0.142nm, and the elastic modulus E
is 910Gpa. But between layers it is 0.335nm and 30 Gpas respectively. Not
only the structure of BN is consistent with graphite but also the lattice
constant is similar. |
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Boron
Nitride (BN) Sputtering targets
Purity--- 99.5% Density---1.9~2.1g/cm3
Shape--- Discs,
Plate, Step (Dia
¡Ü300mm,,
Thickness ¡Ý1mm)
Rectangle, Sheet, Step (Length
¡Ü300mm, Width ¡Ü300mm, Thickness ¡Ý1mm) |
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Boron
Nitride (BN) Evaporation Material
Purity--- 99.5% Density ---
2.25g/cm3
Shape---
Irregularly Piece |
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Boron
Nitride (BN) Boat
Purity--- 95%,98.5%,99.5% |
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Boron
Nitride (BN) Powder
Purity--- 98%, 99.5%
Shape---
Irregularly Piece
Application
--- structure material of atom reactor, spout of plane and rocket, lube of
high temperature, compound cube boron nitride |
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