Introduction of Engineering Materials

   Engineer Materials are classified by two types:


   1. Metals & their alloys ( iron, steel, copper )
   2. Non-Metal ( Glass, Rubber, Plastic )








Metals :

• Metals are polycrystalline bodies, which are having number of deferentially oriented fine crystals.
• Normally major metals are in solid state at normal temperature. However some metals such as Mercury are also in liquid state at normal temperature .
• All materials are high thermal and electrical conductivity.
• Example:- Silver, Copper, Gold, Aluminium, Iron,Zinc, Lead.

Metals are divided by 2 types, 

             1. Ferrous Metals

             2. Non-ferrous Metals

1. Ferrous Material :- 

• All ferrous metals are having iron as common element.
• All ferrous materials are having high permeability which makes these material suitable for construction of core of electrical machines.
• Example:- Cast iron, Wrought iron, Steel, Silicon steel, High speed steel.

2. Non-ferrous metals :-

           All non-ferrous metals are having very low permeability.

           Example:- Silver, Copper, Gold, Aluminium etc.

Non-Metals :

• Non-metals are non crystalline in nature.These exists in amorphic  and mesomorphic forms.
• These are in both solid & gases forms at normal temperature.
• Normally all non-metals are bad conductor.
• Example:- Plastics, Rubber, Leathers, Asbestos etc.