written 5.0 years ago by | • modified 4.6 years ago |
Types of coolants are :
(a) Gaseous type
(b) Liquid type
1) water
2) fatty oil
3) straight mineral oil
4) cutting fluids
5) soluble oils
(c) synthetic coolants
(a) Gaseous type :
These type of cutting fluids are applied through a nozzle under pressure.
e.g. Argon, helium, $co_2$, oil mist, etc.
(b) Liquid type :
1) water :
plain water and NaOH water, containing alkali are used where cooling and washing away of chips are needed during machining.
Also water is most freely available, cheapest and best cutting fluid as it conduct very high heat.
2) Fatty oil :
These oils are used in heavy duty machining work
These oils are costly
It give bad smell after some use
Most popular fatty oil - Lard oil and sperm oil.
3) straight mineral oil :
These oils are used for light duty operation on non ferrous - metals like Al, brass, mg, etc
Mostly used in automatic machines.
This oil can be re circulated and reused.
4) cutting oils :
These are mineral mixed with sulfur or chlorine and animal fats.
These are costly.
Used for special operation like gear cutting, broaching, etc.
5) soluble oils :
An emulsion is a product which when mixed with water, forms milky dispersion's.
It is a mineral oil which contains an emulsifier such as soap.
It has good cooling properties
Used in operation like turning, miling, drilling etc.
Disadvantage is it may corrode the machine tool.
(c) Synthetic coolants :
These are generally non-petroleum products and diluted with water.
These coolants gives high material removal rate.
These coolants can not be reused.
It is mostly used in grinding operation.