Basic Classification of Engineering Materials

          Basically, Engineering Materials are often classified into 2 categories-   

• Metals
• Non-Metals

Metals

Metals square measure crystalline bodies that square measure having a range of differentially orientating fine crystals. unremarkably major metals square measure in solid states at traditional temperature. However, some metals like mercury are in liquid state at traditional temperature. All metals square measure having high thermal and electrical physical phenomenon. All metals square measure having positive temperature constant of resistance. means that resistance of metals increases with the increase of temperature.

Examples of metals – 

Metals are often additional divided into 2 groups-

Ferrous Metals:

All part|metal} metals square measure having iron as a common element. All metal materials square measure having terribly high permeableness that makes these materials appropriate for construction of the core of electrical machines. Examples: forged iron, atomic number 26, Steel, atomic number 14 Steel, High-Speed Steel, Spring Steel etc.

Non-Ferrous Metals :

All non-ferrous metals square measure having terribly low permeableness. Example: Silver, Copper, Gold, Al etc.

Non-Metals

              Non-Metal materials square measure non-crystalline in nature. These exist in amorphic or mesomorphic forms. These square measure in each solid & gases forms at traditional temperature.
          Normally all non-metals square measure unhealthy conductor of warmth and electricity.
Examples: Plastics, Rubber, Leathers, amphibole etc.
As these non-metals square measure having a terribly high electrical resistance that makes them appropriate for insulation purpose in electrical machines.

Difference between Metals and Non-Metals

Property Metals:

1. Structure All metals square measure having crystalline structure
2. State Generally metals square measure softened traditional temperature
3. valance board electrons and conductivity
4. Density High density
5. Strength High strength
6. Hardness Generally hard
7. Malleability Malleable
8. Ductility Ductile
9. Brittleness Generally non-brittle in nature
10. Lustre Metals possess tinny lustre

Non-Metals:

1)All Non-metals square measure having amorphic & mesomorphic  structure
2)State varies material to material. Some square measure gas state and a few square measure in solid state at traditional temperature.
3)Valance electrons square measure liberal to move within metals that makes them smart conductor of warmth & electricity Valence electrons square measure tightly certain with a nucleus that doesn't seem to be liberal to move. This makes them unhealthy conductor of warmth & electricity
4)Low density
5)Low strength
6)Hardness is usually varies
7) Non malleable
8)Non ductile
9)Brittleness varies material to material
10)Generally, don't possess tinny lustre (Except black lead & iodine)

Other classification of engineering materials:

Engineering materials also can be classified as below-

• Metals and Alloys
• Ceramic Materials
• Organic Materials

Metals and Alloys

Metals square measure crystalline bodies that square measure have a range of differentially orientating fine crystals. unremarkably major metals square measure in solid states at traditional temperature. However, some metals like mercury are in liquid state at traditional temperature.
Pure metals square measure having terribly low mechanical strength, that generally doesn't match with the mechanical strength needed surely applications. to beat this flinch alloys square measure used.
Alloys square measure the composition of 2 or a lot of metals or metal and non-metals along. Alloys square measure having smart mechanical strength, coldness constant of resistance.
Example: Steels, Brass, Bronze, Gunmetal, Invar. Super Alloys etc.

Ceramic Materials

Ceramic materials square measure non-metallic solids. These square measure fabricated from inorganic compounds like Oxides, Nitrides, Silicides and Carbides. Ceramic materials possess exceptional Structural, Electrical, Magnetic, Chemical and Thermal properties. These ceramic materials square measure currently extensively employed in completely different engineering fields.
Examples: silicon dioxide, glass, cement, concrete, garnet, Mgo, Cds, Zno, SiC etc.

Organic Materials

All organic material square measure having carbon as a typical component. In organic materials carbon is with chemicals combined with atomic number 8, element and different non-metallic substances. usually organic materials square measure having advanced chemical bonding.
Example: Plastics, PVC, artificial Rubbers etc.