Composite Materials

Composite Materials Definition.

A composite materials ( or composite ) is a structure of materials that is formed by two or more different substances such as metal, glass , ceramics and polymers.

Examples of composite materials and its uses

Composite Materials	Composition	Properties	Uses
Reinforcement Concrete	• Cement • Gravel • Sand • Water • Iron or Steel	∆ Strong ∆ High textile strength ∆ Cheap	- Construction materials
Superconductor	• Niobium • Germanium	∆ Zero resistance ∆ Functions only under extremely low temperatures	- Transportation -Telecommunications - Astronomy industry - Medical field
Fibre Glass	• Silica • Sodium carbonate • Calcium carbonate	∆ Good insulator of heat and electricity	- Protective apparel for astronauts and firefighters
Fibre Optics	• Glass • Copper • Aluminium	∆ Enables information to be transmitted in light form at light speed	- Electrical cables - observe internal organs without surgery
Photochromic Glass	• Molten silica • Silver cloride	∆ Dark in colour when exposed to light and bright when in the dark	- Optical lenses - Glass windows
Ceramic Glass	• Produced by exposing glass that contains certain amounts of metal to ultraviolet rays and heating it at high temperatures		- Cooking materials - Rocket heads
Plastic strengthened with glass fibres	• Plastic • Glass	∆ Very strong ∆ Light ∆ Easily formed ∆ Withstands corrosion	- Helmets - Body of cars and aeroplanes - rods

Comparing the Properties of Fiber Glass with its original components

The process of making glass and fiberglass

Most glass is a mixture of a substantial amount of silica that derived from fine white sand or pulverized sandstone, combined with smaller amounts of an alkali like soda (sodium bicarbonate) or potash to decrease its melting point, and lime (from limestone) to help stabilize the mixture and eventually make the glass vigorous and water-resistant

whereas

At the most basic level, a strand, or fiber, of glass, can be formed by taking molten glass
 (made  by  melting  silica  sand,  limestone,  and  soda ash, along with recycled glass) and forcing it through a small hole. Commercial fiberglass production engages a platinum bushing with up to three thousand holes in it, creating three thousand fibers at a time. 
Even though glass is brittle, these fibers are pretty flexible, because they are so thin.

Advantage of using Photochromic glass in the making of spectacles

Photochromatic lenses are activated by UV radiation. Thus it will darken up the glasses so that it can prevent our eyes from direct lights which leads to retinal damages or Photophobia.

Other than that , Photochromic lenses are great for those that wear eyeglasses, who can not wear sunglasses unless they are prescription. With photochromic lenses, we can carry just one pair of sunglasses or goggles for all day and even night

References:

Reference :

http://uk.answers.yahoo.com/question/index?qid=20101101122225AAUf3aT

http://www.glasstopsdirect.com/how-glass-made.php

http://www.articlesbase.com/outdoor-sports-articles/benefits-of-photochromic-sunglasses-1446939.html