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. |
