Classification of materials

This blog page can be used for a last minute revision on the topic of 'Classification of Materials' from the material science course.

Classification of Materials

- Materials are categorized into three types . They are Metals, Ceramics and Polymers.

Metals

- Metals are composed with one or more metallic elements (e.g. aluminium , copper , iron ). Whereas the non-metallic elements (e.g. carbon , oxygen )are composed with relatively lesser amount .

- The atoms in the metal are being arranged in an orderly manner and are relatively dense.

- Metal alloy is a metallic substance that has two or more elements.

Properties of Metals

-  Stiff
- Strong
-Ductile ( Capable of large amount of deformation without fracture .)
- Good conductors of electricity and heat
- Has non-localised  electrons that are not bound to particular atoms.

Ceramics

 - Ceramics are compounds that are between the metallic and non-metallic elements . Most of the time , they are oxides , nitrides and carbides.

- Examples of ceramics are aluminium oxide  , silicon dioxide  and silicon carbide.

Properties of Ceramics

-Ceramics can be transparent , translucent and opaque.

- Some of the oxide compounds (e.g. Fe3O4 ) consist magnetic behaviour.

Polymers

- Polymers are organic compounds that are chemically based on carbon and other nonmetallic elements . 

- Polymers have very large molecular structures , usually chainlike structure.

- Examples of Polymers are polyethylene , Nylon , Poly(vinyl  chloride ) , Polystyrene (PS) and Silicon rubber.

Properties of Polymers

- Low Density

- Ductile and pliable , which means they can easily formed into complex shapes.