Composite MaterialsComposite Materials

Through ages, man have become more Through ages, man have become more innovative in discovering new materials, innovative in discovering new materials, cost reduction techniques aiding life to cost reduction techniques aiding life to

exist far more better.exist far more better.

What is a composite material?What is a composite material?

often shortened to composites or called often shortened to composites or called composition materials, are engineered or composition materials, are engineered or naturally occurring materials made from naturally occurring materials made from two or more constituent materials with two or more constituent materials with significantly different physical or chemical significantly different physical or chemical properties which remain separate and properties which remain separate and distinct at the macroscopic or microscopic distinct at the macroscopic or microscopic scale within the finished structure.scale within the finished structure.

two materials in which one of the two materials in which one of the materials, called the reinforcing phase, is materials, called the reinforcing phase, is in the form of in the form of fibers, sheets, or fibers, sheets, or particlesparticles, and is embedded in the other , and is embedded in the other materials called the matrix phase. The materials called the matrix phase. The reinforcing material and the matrix reinforcing material and the matrix material can be metal, ceramic, or material can be metal, ceramic, or polymer. Composites are used because polymer. Composites are used because overall properties of the composites are overall properties of the composites are superior to those of the individual superior to those of the individual components.components.

Wattle and daub is one Wattle and daub is one of the oldest manmade of the oldest manmade composite materials, composite materials, at over 6000 years old. at over 6000 years old. Concrete is also a Concrete is also a composite material, composite material, and is used more than and is used more than any other man-made any other man-made material in the world. material in the world. As of 2006, about 7.5 As of 2006, about 7.5 billion cubic metres of billion cubic metres of concrete are made concrete are made each year—more than each year—more than one cubic metre for one cubic metre for every person on Earth.every person on Earth.

Types of CompositesTypes of Composites

Particle-reinforced compositesParticle-reinforced composites

Fiber-reinforced compositesFiber-reinforced composites

Structural compositesStructural composites

Particle-reinforced compositesParticle-reinforced composites

* * Used in particle reinforcingUsed in particle reinforcing

- ceramics, glasses (small mineral - ceramics, glasses (small mineral particles)particles)

-- metal particles metal particles ( (aluminium, and aluminium, and amorphous materialsamorphous materials ) ) polymers polymers and carbon blackand carbon black

Why particles are used?Why particles are used?

Particles are used to Particles are used to increase the increase the modulusmodulus of the matrix, of the matrix, to decrease to decrease the permeabilitythe permeability of the matrix, of the matrix, to to decrease the ductilitydecrease the ductility of the of the matrixmatrix and and also used to produce also used to produce inexpensive compositesinexpensive composites..

Example:Example: CONCRETECONCRETE where the aggregtes ( sand and where the aggregtes ( sand and

gravel) are the particles and cement is the gravel) are the particles and cement is the matrix. Particle reinforced composites support matrix. Particle reinforced composites support higher tensile, compressive and shear stresses.higher tensile, compressive and shear stresses.

Fiber-reinforced compositesFiber-reinforced composites

Fiber-reinforced Composites are made Fiber-reinforced Composites are made of:of:

- metals, ceramics, glasses, or polymers that metals, ceramics, glasses, or polymers that have been turned into graphite and known as have been turned into graphite and known as carbon fiberscarbon fibers..

- Fibers increase the modulus of the matrix Fibers increase the modulus of the matrix materialmaterial. . ((strong covalent bonds along the fiber's strong covalent bonds along the fiber's length gives them a very high modulus in this length gives them a very high modulus in this direction because to break or extend the fiber the direction because to break or extend the fiber the bonds must also be broken or movedbonds must also be broken or moved ) )

Uses of Uses of Fiber-reinforced compositesFiber-reinforced composites sports equipment, such as a time-trial racing bicycle sports equipment, such as a time-trial racing bicycle

frame which consists of carbon fibers in a thermoset frame which consists of carbon fibers in a thermoset polymer matrix. Body parts of race cars and some polymer matrix. Body parts of race cars and some automobiles are composites made of glass fibers (or automobiles are composites made of glass fibers (or fiberglass) in a thermoset matrixfiberglass) in a thermoset matrix

Fiber orientation in fiber reinforced composites.

Structural compositesStructural composites

The properties of The properties of structural structural composites composites depend on:depend on:

- Constituents- Constituents

- Geometrical design- Geometrical design

Common Composite MaterialsCommon Composite Materials< ASPHALT

FIBER GLASS >

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