Composite Materials

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Composite Materials

• Combination of two or more chemically distinct
  and insoluble phases whose properties and
  structural performance are superior to those of
  the constituents acting independently.
• Example addition of straw (reinforcement) to
  clay (matrix) for making mud huts and bricks for
  structural usage.

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Reinforced Plastics

• Consist of fibers in a plastic matrix
• fibers can constitute 10 to 65 of the volume of
  reinforced plastic
• Hybrids are more expensive, but wear less
• Higher fatigue resistance, toughness, stiffness,
  and creep resistance

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Reinforced Plastics

• Reinforcing Fibers
• glass, graphite, aramids (kevlar), boron.
• hybrid (more than one type of fiber is used).
• other fibers nylon, silicone carbide, aluminum
  oxide, steel, molybdenum.
• Matrix Materials
• epoxy (most common)
• polyester, phenolic, fluorocarbon, silicone
• See matrix functions

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Other Composite Materials

• Ceramic Matrix Composites
• resist high temperatures and corrosive
  environments.
• Metal Matrix Composites
• High elastic modulus
• high resistance to elevated temperatures.
• high ductility and toughness
• Aluminum, aluminum lithium, magnesium, titanium

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Other Composite Materials

• Honeycomb Structures
• core of honeycomb, or other corrugated shape,
  bonded (by adhesives or by brazing) to thin outer
  skins.
• light in weight.
• high resistance to bending forces.