This document provides an overview of mechanical engineering and discusses several key sub-disciplines and processes including production engineering, metal forming, machining, casting, and welding. Production engineering involves converting raw materials into finished products through processes like forming, machining, joining, and casting. Metal forming changes a material's shape without changing its mass or composition, and can involve hot or cold working. Common metal forming examples include rolling, piercing, drawing, spinning, extrusion, and forging. Machining cuts material using machine tools like lathes, drilling machines, milling machines, and grinding machines. Metal casting involves melting metal and pouring it into a mold to solidify. Welding fuses materials together using heat, pressure, or

2. Unit -1
Overview of Mechanical Engineering
Mechanical Engineering contributions to the welfare
of Society
• Specialized sub disciplines in Mechanical Engineering
- Production, Automobile, and Energy Engineering
• Interdisciplinary concepts in Civil and Mechanical
Engineering.

3. Production Engineering
 Production engineering is also known as
Manufacturing engineering.
 Production is the process of converting raw
materials into finished products with
minimum cost.
 Production processes such as forming,
machining, joining, and casting.
 Modern machining process

4. Metal forming process

5. Metal forming process
 Metal forming is the process of changing the shape of
a solid without any change in it’s mass or material
compositions.
 In forming process no material is removed instead of
material is deformed.
 Metal forming process may be either hot working or
cold working depending upon temperature and strain
rate

6. Hot working
 In hot working, plastic
deformation takes place
above recrystallisation
temperature but below
melting point.

7. Cold working
 In cold working, plastic
deformation takes place
below recrystallisation
temperature.

8. Example of forming
Rolling
Piercing
Drawing
Spinning
Extrusion
Forging

9. Example of forming

10. Example of forming

11. Example of forming

12. Metal Machining Process

13. Metal Machining process
 In metal machining process or cutting
shaping process, material is cut by a
machine tool to form desired shape.
 Various machine tools are lathe, drilling,
milling, grinding, planer, shaper

14. Lathe machine
 Lathe is a father of all
machine tools
 Cylinders, turbine shaft
are made by lathe
machine
 Automatic lathe such as
a capstan and turret
lathe are also available

15. Drilling machine
 Drilling machine used to
form a hole in the work
piece
 Drilling machine used
multipoint cutting tools

16. Milling machine
 Milling is the process
of machining using
rotary cutters to remove
material by advancing a
cutter into a work piece.
This may be done varying
direction on one or
several axes, cutter head
speed, and pressure.

17. Grinding process
 Grinding is machining
process that's used to
remove material from a
work piece via
a grinding wheel. As
the grinding wheel
turns, it cuts material off
the wor kpiece while
creating a smooth
surface texture in
the process.

19. Metal casting process
 It is the process of
forming metal products
by melting the metal,
pouring it into a cavity
called mould and allow
to solidify
 Green sand moulding is
a best example for this
process

20. Metal casting process

21. Welding process
 Welding is a
fabrication process whe
reby two or more parts
are fused together by
means of heat, pressure
or both forming a join as
the parts cool.
 Welding is usually used
on metals and
thermoplastics but can
also be used on wood.