1 An Overview of Composites

Lamborghini carbon fiber materials chassis. Carbon Fiber Reinforced Plastics.

1.1 Definition of Composites
1.2 Historic Development of Composites
1.3 Classification of Composites
1.4 Applications of Composites

1.1 Definition of Composites

The word " Composite " in composite material signifies that two or more materials are
combined on a macroscopic scale to form a useful material. The key is the macroscopic
examination of a material. Different materials can be combined on a microscopic scale, such
as in alloying, but the resulting material is macroscopically homogeneous. The advantage of
composites is that they usually exhibit the best qualities of their constituents and often some
qualifies that neither constituent possesses. The properties that can be improved by forming
a composite material include :

~ Strength
~ Stiffness
~ Corrosion Resistance
~ Wear Resistance
~ Attractiveness
~ Weight
~ Fatigue Life
~ Temperature-Dependent Behavior
~ Thermal Insulation
~ Thermal Conducity
~ Acoustical Insulation

Naturally, not all of the above properties are improved at the same time nor is there usually
any requirement to do so.

A composite is a combined material created by the synthetic assembly of two or more
components -- a selected filler or reinforcing agent and a compatible matrix binder (i.e a resin...)
in order to obtain specific characteristics and properties. The components of a composite do
not dissolve or otherwise merge completely into each other, but nevertheless do acting correct.
The components as well as the interface between them can usually be physically identified, and
it is the behavior and properties of the interface that generally control the properties of the
composite. The properties of a composite can not be achieved by any of the composite acting
alone.

A composite is a system produced by the assembly (synthetic or metallic) of two or more
materials; namely, a selected reinforcing element and a compatible binder (organic or metallic)
to attain specific mechanical properties. These properties can result in an improved product,
and greater design freedom in engineering the material as well as the structure.

1.2 Historic Development of Composites

We need the material engineers to research and develop materials ...
Northwestern University had established the first materials science academic department in
the world. 

Schematic diagram showing the relative importance of the four classes of materials
(ceramics, composites, polymers and metal) in mechanical and civil engineering as a function
of time. The time scale is nonlinear.

Throughout history, materials have limited design. The ages in which man has lived are named for the materials he used: stone, bronze, iron. And when he died, the materials he treasured were buried with him: Tutankhamen with shards of colored glass in his stone sarcophagus, Agamemnon with his bronze sword and mask of gold, each representing the high technology of his day.

The first FRP (Fiber Reinforcement Plastics) for light airframe structures were conceived,
developed, and designed by the Wright-Patterson Air Force Base, Structures and Material
Laboratory, Dayton, Ohio, in 1943. After analyzing test results on efficient structure could be
designed and fabrication using high-strength fiberglass-polyster resin laminate faces with a
low-density core material.

1.3 Classification of Composites

Classification of Materials

Composites can be classified on the basis of the form of their structural components :
fibrous (composed of fibers in a matrix), laminar (composed of layers of materials), and
particulate (composed of particles in a matrix). The particulate class can be further subdivided
into flake (flat flakes in a matrix) or skeletal (composed of a continuous skeletal matrix filled by
a second material). In general, the reinforcing agent can be either fibrous, powdered, spherical,
crystalline, or whiskered and either an organic, inorganic, metallic, or ceramic material.
Typical resins include polyester, phenolic, epoxy, silicone, alkyd, ...

Classification of Composite

(1) Material Combination
      Metal-Organic
      Metal-Inorganic

(2) Bulk-Form Characteristics
      Matrix System
      Laminates

(3) Distribution of Constituents
      Continuous
      Discontinuous

(4) Function
      Electric
      Struction

Form of the Structure Constituents

(1) Fiber Composites -- composed of fibers with or without a matrix.
(2) Flake Composites -- composed of flat flakes with or without a matrix.
(3) Particulate Composites -- composed of particles with or without a matrix.
(4) Filled or Skeletal Composites
(5) Laminar Composites

Organic Matrix Composites

(1) Powder-Reinforced
(2) Fiber-Reinforced
(3) Laminated

Metal Matrix Composites

Metal matrix composites offer less pronounced anisotropy and greater temperature capability
in oxidizing environments than do the polymeric and carbonaceous counterparts. Although
most metals pr alloys could serve as matrices, in particle the choices are sharply limited.

Ceramic matrix Composites

High temperatures composite -- means synthetic multiphase system of materials intended to
be used at 200 degrees Celsius or above.

Space Shuttle Reusable Ceramic Tiles.

High Temperature Reusable Surface Insulation. (HTRS) From Wikipedia.

Carbon-Carbon Composites

Carbon represents the ultimate high temperature end-member of polymer matrix materials.
It has one of the highest temperature capabilities under non-oxidizing conditions among
known materials (it melts or sublimes, depending on the pressure, at 3500 degrees Celsius).

Hybrid Composites

1.4 Applications of Composites

Everywhere...  no limitation... wait for engineers to explore...

All-new AMG Ceramic Composite.

Carbon-Fibre-Reinforced ceramic in a vacuum at 1700 degrees Celsius, the ceramic discs are much harder. This not only increases the service life many times over compared with a grey cast iron disc, but also their resistance to extreme loads and heat. The result: extremely short stopping distances, exact pressure point and much higher fade resistance even under extreme operating conditions. The larger ceramic discs – front: 402 x 39 millimetres; rear: 360 x 32 millimetres – also feature a composite design and are connected with a floating radial mount to an aluminium bowl. Their braking power of 823 kW/1120 hp during an emergency stop from 250 km/h to zero is again higher than the AMG composite brake system.

Postscript :

This is my undergraduate course : Applications Practices of Composite Materials.
After I watched National Geographic Ultimate Factories (Megafactories) that ignited my
curiosity of manufacturing engineering. Sometimes, reverse the learning process would
facilitate the perception of knowledge.