COMPOSTE

COMPOSITESCEREN ALBA : 12054001MEHMET LATFLER : 12054007SNAN KALAYCI : 12054020MURAT ALTUN : 12054013EBRU DNER : 12054023ECEM GLE : 12054029COMPOSITE . A composite material is made by combining two or more materials .. Often the materials have very different properties.. The purpose is the two materials work together to give the composite unique propertiesExample of CompositeConcrete is a composite material that occured with a mixture of sand and cement

Why Use Composites?The primary reason composite materials are chosen for components is because of weight saving for its relative stiffness and strengthFor example ; carbon-fibre reinforced composite can be five times stronger than steel. However that composites have only one fifth of the weight of steel.Advantages of CompositesComplex shapes are easily accomplished Resistant to corrosion StrengthLow weightReduced costResilience the ability to deform and spring back to their original shape without major damage.Composite structures act as very good insulators

HISTORY OF THE COMPOSITES INDUSTRY

The earliest man-made composite materials werestrawandmudcombined to formbricksforbuildingconstruction. Ancientbrick-makingwas documented byEgyptian tomb paintings.

In the years between 1870 and 1890, a revolution was occurring in chemistry. The first synthetic (man-made) resins were developed which could be converted from a liquid to a solid by polymerization. These polymer resins are transformed from the liquid state to the solid state by crosslinking the molecules. Early synthetic resins included celluloid, melamine and Bakelite.

Composites are no longer considered "space-age" materials utilized only for stealth bombers and space shuttles. This versatile material system has become a part of everyday life.

WHERE ARE COMPOSITES USED?

Composite materials are generally used forbuildings, bridges and structures such as boat hulls, swimming pool panels, race car bodies,showerstalls,bathtubs, storage tanks, imitationgraniteandcultured marblesinksand counter tops. The most advanced examples perform routinely on spacecraft and aircraft in demanding environments.

AIRCRAFT/MILITARYAPPLIANCE/BUSINESSAUTOMOTIVE/TRANSPORTATIONCIVIL INFRASTRUCTURECONSTRUCTIONCONSUMERMARINE

TYPES OF COMPOSITE MATERIALSPolymer matrix composites

Metal matrix composites

Ceramic matrix compositesPolymer matrix compositesThese are the most common composites in use today. Also known as FRP - Fibre Reinforced Polymers (or Plastics) these materials use a polymer-based resin as the matrix, and a variety of fibers such as glass, carbon and Aramid (Kevlar) as the reinforcementMetal matrix compositesIncreasingly used in the automotive industry, these materials use a metal such as aluminium as the matrix, and reinforce it with particles or fibers such as silicon carbide Composites with aluminium and magnesium matrices have been investigated extensively, and recently steel matrix composites have gathered increased interest. In these composites, stainless steels, tool steels and precipitation hardened steels have been used as the matrix material. The particulate reinforcements can be: Oxides CarbidesNitridesBoridesCeramic matrix compositesCeramics have a high compressive strength but low tensile strength. Combining with a high tensile reinforcement gives very strong hard materials. Used in high temperature environments, such as jet engines, CMCs use a ceramic as the matrix and reinforce it with short fibres, or whiskers such as those made from silicon carbide and boron nitride.

FIBRE OPTIC CABLEA fibre optic cable consists of a bundle a glass or plastic threads that are surrounded by a glass cladding.

( a bundle of optical fibers )It is a composite material that is able to transmit data, voice and images in a digital format

Fiber optics has several advantages over traditional metalcommunicationslines: Fiber optic cables have a much greaterbandwidththan metal cables. This means that they can carry more data. Fiber optic cables are less sensitive than metal cables to interference. Fiber optic cables are much thinner and lighter than metal wires.

The main disadvantage of fiber optics is that the cables are expensive to install. In addition, they are more sensitive than wire and are difficult to splice.

(parts of optical fibers cable)

The applications for using fiber optic are communications, sensors and power transmission

Fiber optics is a popular technology forlocal-area networks. In addition, telephone companies are replacing traditional telephone lines with fiber optic cables. In the future, almost all communications will use fiber optics.

FIBRE GLASSGlass is hard, strong and has a relatively high density. However, it is also brittle.Plastic is elastic, flexible with low density but not as strong as glass.When glass fibres are used to reinforce plastc, we get a strong composite material called fibre glass.Fibre glass has high tensile strenght, can be easily coloured and low in density. It can be made into thin layers, yet very strong.

It is also easily moulded and shaped.It has been used to make household products like water storage tanks, badminton rackets. Small boats, skis and helmets.

PHOTOCHROMIC GLASSIt can be produced by embedding photochromic substances like silver chloride, AgCl crystals in glass or transparent polymers.When it is exposed to light, silver chloride, AgCl is converted to silver and the glass darkens.The photochromic glass becomes tranparent again when silver is converted back to silver chloride, AgCl when the light dims.It is sitable for making optical lenses, car windshields, smart energy efficient Windows in buildings, information display panels, lens in cameras, optical switches and light intensity meters.