In Science of material materials receives the name of composed those that fulfill the siguentes properties:

  • They are formed of 2 or component distinguishable and physically separable ones mechanically.
  • They present/display several phases different, insoluble and completely to each other separated chemically by one Intercara
  • Their mechanical properties are superiors to the simple sum of the properties of their components ( Synergy ).

These materials are born from the necessity to obtain materials that combine the properties of the ceramic ones, the plastics and the metals. For example in the industry of the transport they are necessary light, rigid, resistant materials to the impact and that resists the corrosion and the wearing down well, properties these that rarely occur meetings.

In spite of to have obtained material with exceptional properties, the practical applications are reduced by some factors that increase much their cost, like the difficulty of manufacture or the mutual incompatibility between materials.

The great majority of the compound materials is created artificially but some, like Wood and the bone, appear in the nature.

Structure

Although a great variety of compound materials exists, in all can be distinguished the following parts:
  • stiffener Agent : it is a phase of discreet character and its geometry is fundamental the hour to define the mechanical properties of the material.
  • first or simply first Phase: it has continuous character and she is the person in charge of the physical and chemical properties. It transmits the efforts to the stiffener agent. It protects also and it gives it cohesion to the material.

Classification

The compound materials can be divided in three great groups:

Reinforced Compound materials with particles.

Estan made up of particles of a material one lasts uniformly and fragile dispersed discreet and, surrounded by one more a softer and ductile matrix

Types: Hardened by dispersion Formed by true particles

Compound materials reinforced with fibers .

A component usually is a stiffener agent like a strong fiber: Fiber glass, Quartz, Kevlar, Dyneema or carbon Fiber that provides to the material its force to traction, whereas another component (called first) that usually is a resin like Epoxy or Polyester that surrounds and binds fibers, transferring the load of fibers broken to the intact ones and between that they are not aligned with the lines of tension. Also, unless the chosen matrix is especially flexible, it avoids the buckling of fibers by compression. Some compounds use an aggregate instead of, or in addition to fibers.

In terms of force, the fibers (responsible for the mechanical properties) serve to resist the traction, the matrix (responsible for the physical and chemical properties) to resist the deformations, and all the material presents serve to resist the compression, including any aggregate.

The cyclical blows or efforts can cause that the fibers separate of the matrix, which is called delaminación.

Skeletal composite materials.

Estan formed as much by composites as by simple materials and their properties depends essentially on geometry and its design. Most abundant they are laminar and the calls panels sandwich .

The laminar ones are formed by united panels to each other by some type of adhesive or another union. Most usual it is than each lamina is reinforced with fibers and has a preferred direction, more resistant of the efforts. This way we obtain a isotropic material, uniting several anisotropic layers markedly. It is the case, for example, of contrachapada wood, in which the directions of maximum resistance form right angles to each other.

panels sandwich consist of two outer laminae of high hardness and resistance, (normally reinforced plastics or Titanium ), separated by a less dense and less resistant material, ( polymeric frothy, synthetic rubbers, inorganic wood raft or cements). These materials are used frequently in construction, the aeronautics industry and the manufacture of electrical condensers multilayers.

Examples of compound materials

  • Plásicos reinforced with fiber:

    • Classified by the type of fiber:
      • Wood (fibers of cellulose in a lignin matrix and hemicellulose)
      • Carbon fiber reinforced plastic or CFRP or
      • Fiber glass reinforced plastic or GFRP or HTTP: /en.org/wiki/Glass_reinforced_plastic GRP (informally, " fiber of vidrio")
    • Classified by the matrix:
        • Thermoplastic reinforced by long fiber.

        • Thermoplastic glass weaves.
      • Composed termoformados or heat-stable.
  • Composed of metallic matrix or MMCs:

    • Cermet (ceramic and metal).
    • White smelting.
      • Hard metal (carbide in metallic matrix)
    • Laminate metal-intermetal.
  • Composed of ceramic matrix:
    • Concrete concrete/
    • reinforced Carbon-carbon (carbon fiber in graphite matrix).
    • Bone (first bony reinforced with colágeno fibers)
    • Adobe (mud and straw)
  • Composed of ceramic added organic matrix/
    • Madreper it or nacre
    • Concrete asphalt
  • improved Wood

    • Plywood
    • Oriented fiber boards.
    • Trex
    • Weatherbest (recycled wood fiber in polythene matrix)
    • Pycrete (serrín in ice matrix)

Processes of manufacture

  • Moulding by projection
  • Moulding by humid route or contact
  • Piled up by emptiness stock market
  • It draws resin from Moulding Transfer, RTM
  • Vacuum Assisted Resine Moulding Transfer, VARTM
  • It draws resin from Moulding Infusion, RIM
  • Filament Winding
  • Fiber Placement
  • Pultrusión
  • Automatic Tape Laying, ATL
  • Eb couring

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