NICKEL AND ITS ALLOYS

Nickel and its Alloys

Nickel is a hard lusterless white metal and it posses the following properties.

1. It possesses good corrosion and oxidation resistance.
2. It has high tensile strength and can be easily formed hot and cold.
3. It can be fabricated using processes similar for mild steel
4. It can take up high polish.
5. It is Ferro-magnetic of ordinary and low temperature but becomes paramagnetic at elevated temperature.
6. Melting point of nickel is1453^oC

NOTE:- Ferro magnetic: - Strong attraction by the magnetic field

               Para magnetic: - Week attraction by the magnetic field.

Uses and application of nickel:-

1) Nickel is used for in electroplating

2) In electronic and low current electrical application

3) For corrosion protection of iron and steel part and zinc based die-casting used in the automotive field.

4) Incandescent lamp and radio industries

5) In permanent magnet

6) In the chemical industry for the construction of evaporators tanks, heating coils and tubular condensers.

Types of Nickel alloys:-

A) Nickel-copper alloys

The major nickel base alloy with copper in Monel

Properties of Monel

1) It has a brighter appearance than nickel

2) It is stronger than mild steel

3) It has excellent resistance to atmospheric and sea water-corrosion

4) Generally it is more resistant than nickel to acid, less resistance to alkalis and equally resistant to salt.

Uses and application of Monel

     Monel is used in architectural and marine application where appearance and corrosion resistance is important and in specialized equipment used by the food pharmaceutical, paper, oil and chemical industries.

B)  Nickel- Copper- Zinc alloys (nickel silver )

      Nickel copper zinc alloys the known as nickel silver, do not contain silver and in actually they are brasses with sufficient nickel added to give a silvery white color improved corrosion resistance and high strength.

     These alloys are used as low cost substitutes with silver in tableware and jewellary usually with silver or gold electroplate on the surface.  Nickel silvers are also construction material for many musical, drafting and scientific instruments and also used for marine and architectural parts.