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Introduction Difference
with other materials
Advantages
of composites
Type
of Composites
High
Strength Fibres
Matrices
Production
Methods
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INTRODUCTION
This page gives general
introduction of composites for people and companies who are interested in
the possible use of composites for their products, or are first time users
and want to know a little bit more (by example: are interested in
solving engineering /product problems with composites materials). What
are composite materials (definition) ? A
combination of two or more materials (reinforcing elements, fillers and
composite matrix binder) differing in form or composition on a
macro-scale. The constituents retain their identities: that is, they do
not dissolve or merge completely into one another although they act in
concert. Normally, the components can be physically identified and exhibit
an interface between one another. [ref:
ASM International, engineered materials handbook volume 1.
"Composites"] History
facts / Did you know ! Plywood
(invented by the Egyptians, approx. 1500 BC), and reinforced
concrete (invented by the Romans , approx. 1000 BC), but also
natural fibre reinforced clay (used by Men before iron was invented) are
in essence composite materials. And now we (re-)develop new advanced
technologies using natural fibres in composites again ! DIFFERENCES
WITH OTHER MATERIALS
TOP The
basic difference of composite materials with by examples metals is that
they have a An-Isotropic behaviour, which means that the habits of
the composite material or formed laminate are directional depended. Metals
have in general an Isotropic behaviour, which means that their habits are
in all directions the same. Some other differences are:
-
End material is
formed during production process, in most cases in the end form of the
end product.
-
Materials habits are
also determined by production/curing process
-
Fibrous composites
are more versatile than metals and can be tailored to meet performance
needs and complex design requirements.
-
Higher specific
strength (material strength/density material). Aramide and Carbon
Fibre reinforced epoxies have approx. 4 to 6 times higher spec.
tensile strength than steel or aluminium
-
Great fatigue
endurance especially for aramide and carbon reinforced epoxies,
compared with metals.
-
etc.
ADVANTAGES
OF COMPOSITES
TOP
-
Very high specific
strength. Which means very high strength and low weight
-
Great freedom of
shape. Double curved and complex parts can be simple produced.
-
High degree of
integration possible. Which means simple integration of stiffeners,
inserts, cores, and production of self supporting structures in one or
two production cycles.
-
Material can be
tailored. Which means fit for the loads / performance the end product
has to perform during its lifetime
-
Excellent fatigue
endurance concerning number of load cycles (many times higher than
with metals) and residual fatigue strength (aramide and carbon epoxy
laminates retain more than 60% of their residual static strength,
which is far more higher than is possible with metals.)
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Excellent chemical
resistance against acids, chemicals etc.
-
Excellent weather/water
resistance. Material has almost no corrosion, takes on little water
which leads to low maintenance cost especially on the long run.
-
Composites have
excellent RAM features (Radar absorbing materials). It's also possible
to make special laminates which are radar and sonar transparent.
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Excellent impact habits
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Excellent electrical
habits, concerning isolation but also conduction, dielectric habits, EMS
shielding etc. Structures can be tailored on RF transparency but can
also be made RF reflecting. Great for telecom especially UMTS frequencies.
-
Great thermal isolation
habits, fire retardancy habits, and high temperature performance
-
etc.
TYPES
OF COMPOSITES
TOP The
most known type of composites are the fibre reinforced plastics. However
there are more types of composites, in which also metals are used !. Types
of composites are:
-
Fibre reinforced
plastics
-
Fibre reinforced thermo set
plastics (like polyester, vinlyester, epoxy, BMI/Polyimide,
phenol, etc.)
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Fibre reinforced
thermoplastics (like PPS, PEEK, PEI, PAI, etc.)
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Sandwich structures
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FRP facings,
aluminium facings, steel facings and foam (PUR, PIR, PVC etc.)
and/or honeycomb (nomex, aluminium, carbon, etc.) core's
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Fibre metal laminates (FML's
like ARALL and GLARE)
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Metal Matrix Composites
(MMC's)
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Glass matrix composites
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Ceramic Matrix
Composites
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Ceramic Ceramic
Composites
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Carbon Carbon
Composites
-
etc.
HIGH
STRENGTH FIBRES (most
known)
TOP
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glass fibre (E-glass,
S-glass, C-glass)
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quartz fibre
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organic fibres
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aramide (Twaron /
Kevlar)
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zylon
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polyethylene fibre
(HPPE-->Dyneema / Spectra)
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M5 fibre (under
development by Magellan). http://www.m5fibre.com
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carbon fibre (HT and
HM)
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boron fibre
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ceramic fibres,
alumina, carbide and nitride
Fibres
MATRICES
(most
known)
TOP
PRODUCTION
METHODS (most
known)
TOP
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hand lay-up (thermo sets
and prepregs)
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spray up (thermo sets)
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cold press (thermo sets)
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GMT and BMT (SMC and
BMC)
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injection moulding
(thermoplastics)
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vacuum infusion and
vacuum injection (VI-RTM)
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Resin Transfer Moulding
(RTM of thermo sets and ceramics, fibre preforms 3D woven and braiding
)
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compression moulding (prepregs
and thermoplastics, glass, ceramics and metals)
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pultrusion (thermo set
and thermoplastics)
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filament winding (thermo set,
thermoplastics and ceramics)
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vacuum bagging (prepregs
lay-up and cure in oven)
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autoclave (cure under
pressure and high temp, thermoplastic, thermo set, ceramics, MMC's,
FML's)
-
etc.
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Some
Examples
To be included Graph
and diagrams specific
strength
comparison of fibre
laminates/metals table
of some
mechanicals values reference
/ links / literature CTP
paper (PDF)
Use of phenol for marine, offshore, building and construction industry Fire
Hard Composites for Architectual Applications
Fire retardant composites for Marine industry
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