Properties of materials

Materials
All chemical substances that are used to build or manufacture an object are called material. Materials can be raw materials, manufactured materials or alloys. Each materials have their own set of properties which make them unique and suitable for something. Some materials may have the similar properties but rarely the same set of properties.

Types of materials
There exist many types of materials around the world but the most common main types amongst them are; wood, metal, plastic and stones.

Wood/Lumber: comes from trees which are cut down into wood logs and sawn into different sizes.

Metal: comes from minerials, normally in rocks, from which they are extracted. Most of them can be from in periodic tables.

Plastic: plastic are waste products extracted from rough petrol.

Properties of materials

Brittleness: Ability of material to break without significant deformation when under stress

Hardness: Ability of material to withstand surface deformation and stratch

Toughness: Ability of material to absorb energy and withstand shock without fracturing, rupturing or breaking

Malleability: Ability of material to be deformed of flattened under application of compressive forces without failing.

Ductility: Ability of material to deform under tensile load

Plasticity: Ability of material to deform permanently without failing

Elasticity: Ability of material to deform temporarily under stress and return to it original state (size and shape) when stress is removed

Durability: Ability to resist pressure, wear or ensile strength damage with repsect to time

Tensile strength: maximum stress that a material can resist before tensile failure

Compressive strength: maximum stress can resist before compressive failure

Heat capacitance: Ability to absorb and re-emit heat without failing

Electric capacitance: Ability to absorb and re-emit electricity without failing

Stability: Ability of material to remain stable in terms of atomic structure.

Alloys
Alloys is a mixture of 2 or more substances. These mixtures create another mateirals with more charateristics than the original ones. For example, glass is hard  and brittle whereas plastic is tough and malleable but none of them can be used for car body. Glass will not be able to reisist shock as it is too brittle but plastic is too malleable as it will deform with a little force applied. Glass Reinforced Plastic (GRP) which also called as fibre-glass, is a mixture of glass fibres and plastic resin. The final mixture gives a product consisting with all the four characteristics.

Choosing the approiate material
Eventually, choosing suitable materials depends on "what properties are required". As explained, some materials may have the same set of properties but their are other factors that differentiate them such as; price, aestetic, durability and working time. Of course these factors are to be considered when choosing which material to use to manufacture a product. Material's choice should be done at the development stage of a product and it depends on the requirements of the product; functionality, stability, proportion, antropometrics and ergonomic.