Materials

Classification of materials

Technology Department

General classification
1. Metals and alloys 5. Composites Materials 2. Polymers

4. Ceramic materials

3. Woods

1. Metals
► Metalsare usually lustrous, ductile, malleable, and good conductors of electricity ► They are divided into 2 categories: FERROUS: the group which contains mainly iron (Fe). Iron is the most importantmetal in industrialized countries NON-FERROUS: other metallic materials containing no iron like copper (Cu) or aluminium (Al)

2. Polymers
► Crude

oil supplies the majority of the raw material forthe production of polymers, also called plastics ► Polymers can be divided into 3 categories: Thermoplastics: usually soft and easy to be recycled Thermosetting plastics: usually stiff and not easy tobe recycled Elastomers: flexible (rubbers)

3. Woods
► Different

species of tree provide many types of wood or timber ► Manufactured boards such as plywood or MDF are widely used nowadaysPine wood (natural), plywood and Mediumdensity fibreboard or MDF (manufactured)

4. Ceramic materials
word ceramic is derived from the Greek word keramikos. The term covers inorganic non-metallicmaterials whose formation is due to the action of heat ► Clays, bricks, cements, glass are the most important ones
► The

Clay (to make pottery), bricks, cement and glass

5. Composites
►Bonding

2 or more materials together changes their properties and characteristics ► Bonded materials are called Composites

Aluminium honeycomb composite panel, light and strong

Kevlar is used inbullet-resistant vests. It’s a tough and light material

Modern tennis racquets are made of carbonfibre composite

Past and Present

In prehistoric times humans made tools and weapons usingSTONE, WOOD and BONES

With modern technology we can use a wide range of metals, polymers, ceramic materials and composites, like the bodywork of a Formula-1 race-car, made or carbon-fibre composite...