Composite material

Composite materials (or composites for short) are engineering materials made from two or more components. One component is often a strong fibre such as fiberglass, quartz, kevlar or carbon fibre that gives the material its tensile strength, while another component (called a matrix) is often a resin such as polyester or epoxy that binds the fibres together, transferring load from broken fibers to unbroken ones and between fibers that are not oriented along lines of tension. Also, unless the matrix chosen is especially flexible, it prevents the fibers from buckling in compression. Some composites use an aggregate instead of, or in addition to, fibers.

In terms of stress, any fibers serve to resist tension, the matrix serves to resist shear, and all materials present serve to resist compression, including any aggregate.

Examples of composite materials:

• Fibre reinforced plastics:
  • Wood (cellulose fibers in a lignin and hemicellulose matrix)
  • Glass-fibre reinforced plastic or GRP (informally, "fiberglass")
  • Carbon-fibre reinforced plastic or CRP
• Metal matrix composites or MMCs:
  • cermet (ceramic and metal)
    • White cast iron
    • Hardmetal
• Ceramic matrix composites:
  • concrete
  • Reinforced carbon-carbon (carbon fibre in a graphite matrix)

• Chobham armour (see composite armour)
• Plywood
• Weatherbest