Composite Materials Flashcards
_______ is the combinations of two or more materials that differ in composition or form.
Elements do not mix or dissolve but it remains identifiable.
Composites
What is the usual bonding substance used for composites?
Matrix
Where does the strength of a composite structure comes from?
Reinforcing Material
What is the third element of a composite between matrix and reinforcing material?
Interface
- Very high strength to weight ratio
- Easy to produce complex and aerodynamic shapes
- High degree of elasticity. Like fish rod
Advantages of Composites
When a composite airplane structure fails. Will they completely fail?
Yes, because nature of these parts usually doesn’t exhibit any signs of impending failure. (eg - cracks)
Common reason that weaken composite structures?
Moisture from (Water, oil, fuel etc)
Composites are very expensive eh?
Yeaaaa
Type of fiberglass from magnesia-alumina and is used where a very high tensile strength needed.
S-glass
______ Most commonly known as Kevlar. Manufactured by Dupont company.
Exceptional flexibility, Non-conductive, and does not react with metals.
Aramid
____/____ fibers are produce through a heating process of organic fibers in an inert atmosphere.
Carbon/Graphite
Carbon fibers are produced at a temperature of approximately ______ and are approximately 93% - 95% carb
2400° F
Graphite fibers are produced at a temperature of approximately ______ to ______ and are more than 99% carbon
3450°F to 5450°F
Carbon/Graphite composites will produce corrosion when bonded to _____?
aluminum or steel
What does technicians use to separate carbon/graphite from metallic structures?
sealants and corrosion barriers
Fiber style that only used for military applications and extremely expensive.
Very toxic to human health.
Boron
Fiber style that is a synthetic that is exposed to very high heat approximately 2200° F.
Produces very high temperature resistant walls. (Eg. combustion chamber)
Ceramics
For any kind of composite structure, the greatest strength can be attained by having of the fibers _______.
aligned in one direction
_______ fibers are ones in which all of the major fibers run in one direction, and provide maximum strength in only that direction.
Unidirectional fibers
_____ fabrics are fabrics where the major fibers are woven so that they run in two (2) or more directions
considered as WOVEN FABRICS
warp and fill are equal and can use different materials
Bi-directional / Multi-directional
Interface.
1um (micrometer) = 1millionth of a meter
1/1000 or 0.001
1) Fiberglass. (E-Glass and S-Glass)
2) Aramid (Kevlar)
3) Carbon Fiber (Manufactured at 2400°F)
4) Graphite Fiber (Manufactured between 3450°F – 5480°F)
5) Boron Fibers (Core filament of W)
6) Ceramics (Able to withstand High Temperature
Reinforcing Fabric types
fabrics are woven on a large machine called a ______.
Fabric Loom
Plain weave example:
to be uploaded
________ are fabrics that consist of chopped fibers that are compressed together.
Not designed to take high stress loads.
It build up the size of a composite construction
Mat fabrics
mat fabric picture
to be uploaded
2 general categories of matrix:
Thermoplastic and Thermosetting
Very early thermosetting matrix formulation. It is a 2 part compound where there is a resin and a catalyst.
Exothermic reaction happens when 2 materials are mixed. Substance becomes HARD.
Polyester Resin
Biggest drawback for polyester resin:
Fucking dangerous
it SHRINKS and lack of structural rigidity
highly flammable and toxic
They consist of a two part system. One part being the resin and the other being the catalyst.
They have outstanding adhesive, strength and moisture resisting qualities.
_______ are very good at bonding dissimilar materials such as metal parts with composite parts.
Thermosetting epoxy resins
