CARBON FIBRE
Question 1: (a)
Give an account
of the preparation
properties and industrial
uses of carbon
fibre.
Carbon fibres
alternatively called graphite
fibre or carbon
graphite is a
material consisting of
extremely thin fibres
about 0.0002-0.0004 inches (0.005-0.010) in
diameter and composed
mainly of carbon
atoms. The carbon
atoms are bonded
together in microscopic
crystals that are
more or less
aligned parallel to
the long axis
of the fibre. The
crystal alignment make
the fibre incredibly
strong for its
size. Several carbon fibres
are twisted together
to form a
yarn, which may be
used by itself
or woven into
a fabric. Carbon fibres
can be combined
with plastic resins
and wound or
molded to form
composite material such
as carbon fibre
reinforced plastic. To
provide a high
strength to weight
ratio material. Density of
carbon fibre is
considerably lower than
the density of
steel making it
ideal for application
requiring low weight.
PROPERTIES OF
CARBON FIBRES
1 High tensile
strength
2 Low weight
3 Low thermal
expansion
APPLICATION OF
CARBON FIBRES
1 They are
in geo space
2 Military
3 Motor sports
along with other
competition sport
STRUCTURE OF CARBON
FIBRES
The atomic
structure of carbon
is similar to
that of graphite
consisting of sheets
of carbon atom(graphene
sheets) arrangement in a
regular hexagonal pattern.
The difference is the way
these sheets interlock..Graphite is
a crystalline material.The
high nitrogen content
of chitin makes
it useful as a
checking agent.
When
graphite or boron fibres
are used in
place of glass
fibres too is
used rather than
roving(as in bundle
of) bonds between
the sheets are
relatively weak Van
der waal forces given
graphite its soft
and brittle characteristics.
FABRICATION
TECHNIQUE
Carbon
fibres derived from polyacrylonitrile
(PAN) are turbostratic,whereas carbon fibres derived from mesophase pitch are
graphite after heat treatment temperatures exceeding 2200C
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