There are many types of materials which applying for
producing grinding wheels.
Fused Alumina: which is a synthetic aluminum
oxide and made from bauxite by an
electro thermal smelting
process.
The variety of fused alumina
which usually applying in order to production of
grinding
wheels are as follow :
- White fused alumina
(WFA)
It's hard and brittle and use for the
application of all kind of bonded abrasives,
surface grinding of low or unalloyed steel
up to 62 HRC. gear grinding, thread
grinding; precision grinding of hard and
anti - corrosive steels.
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- Brown fused alumina (BFA)
Brown fused alumina (Regular aluminum oxide)
is a particularly tough form of
aluminum oxide. Its toughness
is due to the presence of 3% of
titanium oxide.
It's suitable for producing resinoid and
ceramic bonded
wheels, also it's using for rough grinding
and deburring
of low alloyed steel and cast Iran material.
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- Pink fused alumina (PFA)
PFA, is another form of highly refined
aluminum oxide which contains a small
proportion of chromium oxide (less
than 0.3%).
It's very hard but a little less brittle
than WFA and therefore less impact-sensitive
specially at the edges.
It's specially suitable for production of
vitrified bonded
abrasives for working hardened steels and
alloys with
tensile strength of over 50kg/mm2.
It's used in tool grinding, saw and knife -
sharpening application, precision grinding (e.g
cylinders, etc.) profile grinding, flute
grinding , tooth flank grinding, dry
grinding
of blade segments and mounted points wheels.
- Other types
There are another types of fused alumina
such: Dark Red, Sol gel, Semi pure, Mono
Crystalline and etc. which are consuming for
production of specific
grinding wheels.
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Silicon Carbide: It's smelted out of
quartz sand and oil cake in electric furnaces
at the temperature of app. 2100c which
some fluxes add to the mixture
for reaction acceleration.
It's harder than fused alumina and are also
more brittle.
There are two varieties of silicon carbide. |
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- Black Silicon Carbide
(BSC)
It's very hard and less brittle than green
silicon carbide. It's hardness is about 63HRC
and applied for grinding metallic and non
metallic work piece with low tensile
strength, gray, chilled and malleable cast
iron before annealing, brass, bronze,
aluminum and etc.
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- Green Silicon Carbide
(GSC)
It's particularly hard, very brittle
abrasive with a hardness about 63HRC .
This abrasive is used primarily for
processing hard metals and ceramic cutting
materials, glass and also acid-resistant
steels with austenitic structure.
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Diamond:
Diamond abrasives may be either natural or
synthetic .
Using of diamond grinding wheels
recommend for grinding of cement tungsten
carbides, specific tool grinding and etc.
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Cubic Boron Nitride (CBN):
It's super hard and friable .CBN uses for all
types of hardened steel up to 70 HRC.
CBN abrasives used for precision grinding ,tool
grinding ,surface grinding and etc. |
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