 Carbon
is the most widely and with large quantities used material for
friction pairs in mechanical seals..
Carbon has following specifications: good performance of self
lubricate and lower friction coefficient, anti-corrosion,good
performance of warm-keeping, good heat spread and lower coefficient
of linear expansion, material pairs can matched good, easy to
be processed.
Carbon used for mechanical
seals are mainly divided as following types:
1) Resin
carbon: resin carbon can be divided into hard
resin carbon and soft-electronic carbon. The impregnated stuff
are: organic resin, inorganic and metals. Talbe 3-27 and talbe
3-28 shows the code and performance of the carbon used for
mechanical seals.
2) Hot
pressed resin: crush the carbon after it was
sintered, use phenolric resin or epoxy resin as the bonding
agent£¬after mixed the carbon and phenolric resin or epoxy
resin then press and sinter to make the final product. But
it is poor at heat spread, higher coefficient of linear expansion,
it can be applied for large scale production, lower costs,
maily used in lower burthen mechanical seals such as water
cooling pump, household appliance etc.
3) Pyrolytic
carbon: the pyrolytic carbon made in China
is produced by the process that pyrolytic the hydrocarbon
such as propylene at the high temperature£¬make the carbon
steam infiltrate into air hole of porous body of carbon to
full in the air hole, that will lead the carbon became high
density, less air hole£¬poor permeability to air. It can be
used to the high temperature, strong corrosive environment,
but it is not suitable to used in large scale production,
so it¡¯s cost will be higher if it is used as the material.
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