Composite Materials Combination of two or more chemically

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.

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

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

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

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.