Composite And Non Metallic Flashcards
What is a composite material
Two or more materials joined together to make a strong structure
What are the advantages of composites materials
- High strength-to-weight ratio
- Reduction of parts and fasteners
- Reduction of wear
- Corrosion resistance
What are the disadvantages of composite
Generally expensive
Not easy to repair
What is nomex
very high thermal stability and temperature and flame resistance
Manufactured as a fibre
Gives major strength when combined with a matrix
What is nomex used for
Flame proof clothing
Primary flight controls
What is the relationship between nomex and Kevlar
Contrast chemical isomer
What is fibre glass
Made of Sillica glass spun into cloth
Weights more and has less strength than other fibers
Low cost
What are the 2 types of fibre glass
- E-glass highly resistant to electricity
* S-glass very high tensile strength
What are the characteristics of fibre glass
◦ Low density (2.1 g/cm3)
◦ High Strength
◦ Hight fracture toughness
◦ Circular cross-section and smooth surface
◦ Good ‘wet out’
◦ The fibre does not absorb water/humidity
◦ The fibre is not ductile (ceramic properties)
◦ For sanding, aluminium-oxide or silicon-carbide sand paper can be used. Silicon-carbide will last longer than aluminium-oxid
What are the characteristics of aramid fibre
◦ Low Density (1.45 g.cm3) ◦ High tensile strength ◦ Heat resistance up to 260°C ◦ Non-flammable and non-fusible ◦ Good chemical resistance ◦ Very good resistance against abrasion ◦ High toughness
What is aramid fibre
Yellow colour
Repaired with fibre glass
What is aramid used for
Rotor blades
Bullet proff vests
Use for leading edges
What is kevar
Man made
Organic fibre
What is Kevlar used for
Aircraft panels
Belts for radial Tyree
Bullet proff vests
What are the advantages of Kevlar
High tensile strength
Flexible
What are the disadvantages of kevlar
Absorbs up to 8% moisture
Poor compressive properties
Can’t be used to UV light
Difficult to cut
What are the advantages of carbon fibre
High strength High stiffness Low density Light weight High temperature resistance
What are the disadvantages of carbon fibre
Electively conductive
Can only the cut with air tools
Expensive
What is the relationship between Kevlar and graphite
Graphite is stronger in compressive strength than Kevlar, however, it is more brittle than Kevlar.
What happens with graphite is bonded with aluminium
Will become corrosive
Very course
What is the warp
Runs along length of fabric
What is the weft/fill
Runs perpendicular to the warp fibres.
What is the bias
The bias runs at 45° to the warp threads
What is the selvage edge
Runs parallel to the warp