OM & IS 1.0 Surface Treatment

Surface-treating processes are chemical or mechanical in nature and alter the surface characteristics of the
metal.
Eleven Types of surface treatment are briefly described below:
1) Anodizing: It is an electro-chemical process which gives a slight anticorrosion protection and improves
the appearance of the product. Unlike other types of surface treatment, this does not increase the
dimensions of the object. This gives a better finish. It is used in case of utensils, household appliances
etc.
2) Enamelling: It is a process that bakes on a white, brittle protection finish.
3) Galvanising: It is a hot-dip process which provides an anti-rust zinc coating. Zinc is used for this
purpose. This makes the surface of the metal anti-corrosive and gives a better finish.

4) Honing: It is an abrading operation for hole finishing done by a tool fitted with a bonded abrasive
stone.
5) Lapping: It is a surface smoothing operation by hand or machine.
6) Painting: It will yield protective coating and better appearance.
7) Plastic coating: This process is more durable than painting.
8) Plating: It is an electrolytic process. This can be done with the help of silver, chromium, cadmium,
nickel and copper. Plating provides anticorrosive finish.
9) Shot Blasting: Small shots usually in the form of iron balls are made to blast on the metal required for
making it resistance to wear and tear, remove the stresses and hardness.
10) Shot penning: It is air blasting the small shots against the metal surface in order to increase the hardness
of surface.
11) Tumbling: Castings are tumbled in a tumbling barrel together with an abrasive substance. The friction
created in this way will clean the surface.
Other surface treating processes may be such as:
• Buffing etc.
• Polishing,
• Power brushing,
• Sandblasting,
• Washing,
• Waxing