Presented by :
chandra shekhar vishnoi

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Introduction
Object of mfg process is to produce piece of specified shape and material properties.
Any of the following three type of operations may be employed for the same:
1. Constant Mass Operation (Casting, rolling etc.)
2. Material Addition Operation (Welding, Bolting, riveting etc)
3. Material Removal Operation (Machining, grinding, lapping etc)
Machining Processes
1. Here specified shape is imparted to the work piece by removing access of material in form of chips in conventional methods.
2. This is done by interacting the work piece with tool.
Region of heat generation
1. Primary shear zone
2. Secondary shear zone
3. Tertiary shear zone
% of heat generation in every zone
1.80-85% heat is generated in the shear zone .
2.15-20% heat is generated due to chip tool interface.
3. 1-3% heat is generated due to tool work interface.
Disadvantages of heat generation
1.The hardness of tool is decreased.
2. Melting of tool metal.
3.The wear rate of the tool increases resulting in a decrease in the useful life of the tool .
4. The thermal stresses developed due to high temp. also contribute to the failure of the tool.
5. Built up edge formation
Variation of temperature with cutting velocity
Experimental method of determinig tool temperature
1. Tool –work thermocouple technique
Setup for tool work thermocouple technique
Function of cutting fluids
1. it must act as a lubricant. By reducing friction, it reduces the heat generated.
2. The cutting fluid must also act as an effective coolant.
3. It should act as an anti weld agent to counter act the tendency of the work material to weld the tool under heat and pressure.
Types of cutting fluids
1.Straight oils
2. Soluble oils
3.Semi synthetic fluids
4. Synthetic fluids
5. Gases
Selection of cutting fluids
a. Cooling effect
b. Lubrication effect
c. Taking away formed chip from the cutting zone
Method of applying cutting fluids