Composites and Advanced materials

This blog page can be used for a last minute revision on the topic of 'Composites and Advanced materials' from the material science course.

Composites

- Composites are made up of two or more individual materials.

- A huge number of composite types are being represented by the various combination of metals , ceramics and polymers.

-Examples of composites are wood or bone .

- Well , the most common composites is the fiberglass , where the glass fibers are being embedded within a polymeric material.The glass fibers are very strong and stiff  but also brittle. Whereas , the polymer will be flexible. These make the fiberglass a relatively a stronger , stiffer and also flexible material.

                                                   Fiberglass Composite

Advanced materials

- Advanced materials are that materials that are used in  high - technology applications. Advanced materials includes Semiconductors , Biomaterials , Smart Materials .

Semiconductors

- Semiconductors have electrical properties that are intermediate between the electrical conductors (e.g. metal , metal alloys ) and the insulator s.Electrical characteristics of this materials are extremely sensitive to the presence of minute concentrations of impurity atoms where the concerntrations may be controlled over very small spatial regions.

Biomaterials

- Employed in components into the human body to replace the diseased or damaged body parts . These materials must not produce any toxic substances and must be compatible with body tissues .

Smart Materials

- A group of new and state of the art new materials developed which will have a significant influence on many of our technologies . The components of a smart material include same type of sensor and an actuator.

Types of materials used as actuators

-Shape memory alloys

-piezoelectric ceramics

- Magnetostrictive  materials

- Electrorheological / magnetorheological fluids

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. 

WORLD OF MATERIALS SCIENCE AND ENGINEERING

Material Science and Engineering is a huge field with a lot of aspects to it . It is divided into two parts which is material science and material engineering . As for material science involves investigating of the relationships which exist between the structures and the properties of the materials. Whereas , the material engineering is about designing or engineering the structure of a material to produce the predetermined set of properties.