| Silicon
carbide is the new material for the mechanical seals following
up the above mentioned ceramic. It has light gravity, higher
strength, Lower coefficient of friction, anti-radialization,
self-lubricate, easy to be matched with other materials, stable
chemical Characteristics, heat resistance and good heat spread
etc. Silicon carbide is a kind of brittleness material, weak
in anti-mechanical strike.
There are 4 types of silicon carbide widely used in mechanical
seals, according to the different production procedures, and
all of them have different performances.
1)reaction bond SIC:
It is a impermeable sintered material and made up of SiC and
Si, there are 10-20% dissociative Si in reaction bond SIC,
dissociative Si is the useless matter in reaction bond SiC,
it is weak of anti strong alkalescence and oxidation media.The
advantage of reaction bond is that the final finished products
has the lower contractility, reaction bond SIC good on anti-heat
strike, so it can be used to large scaled production and make
the costs decreased.
2)Sintered SiC:
It is made by pressed the mixed super fine SiC powder and
proper dosage additive and bond., then Sintered them at with
the high temperature from 2000 to 2200 degree centigrade.
It can be applied to the mechanical Seal production which
requires small quanities and various specificationshot pressed
SiC It is made by add proper additive into SiC powder (which
granularity less than 1 μm, then remove them in to the carbon
mold and heated at the hot pressed oven under the temperature
2000 to 2100 degree centigrade while plus 30-50Mpa pressure,
hot pressed SiC has the best chemical stability among all
the SiC materials. It should be used in the anti corrosive
friction pairs.
3) Gas-Permeation
SiC It has the advantages both of carbon and SiC, so it is
a quite prospect material carbon-based Composite material.
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