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1. Welcome to Metal Forming Course
D. Ravi Kumar
email: dravi@mech.iitd.ac.in
Tel: (2659) 1144
M: 9968475190
Office: II-357
TAs: Archit, Srijan, Vinay and Reeturaj

2. Metal Forming – Course Contents
Lecture Class Topic
1 Fundamentals of Metal Forming
2 Plastic Deformation of Materials
3 Bulk Forming Processes
4 Sheet Metal Forming Processes
5 Advanced Forming Technology
Practical Class Topic
6 Spinning, Nibbling and Vacuum Forming
7 Rolling, Blanking, Deep drawing and Bending
8 Formability Test and Simulation
9 Forging and Extrusion Simulation
Practical classes will be held in Sheet Metal Shop
(Central Workshop) and DFM Lab (II-429)

3. Suggested books for reference
1. Metal Forming Handbook: Schuler (Springer)
2. Manufacturing Processes for Engineering Materials:
S. Kalpakjian and R Schmid (Pearson Education)
3. Fundamentals of Modern Manufacturing: M. Groover
(Wiley).

4. How is a beverage can manufactured?

5. Manufacturing of Al sheets

6. Manufacturing of beverage cans

7. Value Addition

8. Forming of cast products

9. Fundamentals of Metal Forming
• A metal forming or a metal working operation
is a plastic deformation process in which the
volume and mass of metal are conserved and
the metal is displaced from one location to
another.
• The primary objective of a metal forming
process is to convert cast products like ingots
and billets into useful shapes such as tubes,
rods and sheets.
• Equally important is the control of mechanical
properties by the metal working processes.

11. Classification of MF processes
Based on applied stress state:
• Direct compression - Forging, rolling. Metal flows
perpendicular to the direction of major principal
stress.
• Tension and compression- wire drawing, deep
drawing
• Pure tension: stretch forming
• Bending: Application of bending moments to the
sheet
• Shearing: Application of high shear forces to
cause the rupture of metal in the plane of shear.

12. Classification of forming processes
• Bulk forming processes
Ex: Rolling, Forging, Extrusion, Drawing etc.
• Sheet metal forming processes
Ex: Deep drawing, Stretching, Bending etc.

13. Bulk Deformation Processes

14. Products of Bulk Forming Processes

15. Sheet Forming Processes
• Deep Drawing
• Stretch forming
• Bending
• Shearing
• Embossing
• Coining

16. Products of Sheet forming

19. Materials for aircrafts
Material Airbus A350 Boeing 787
Plastics and Composites
Al alloys
Ti alloys
Steel
Others
40%
31%
14%
9%
6%
50%
20%
15%
10%
5%

20. Classification of Metal Forming Processes
Based on the temperature of working:
➢ Cold working : Below the recrystallization temp
(< 0.3 Tm)
➢ Warm Working: 0.3-0.5 Tm
➢ Hot working: above the recrystallization temp
(0.5-0.7 Tm)

21. Mechanical Working
Cold working Hot Working

22. Hot working Cold working
1.Temp of working above
Trecryst.
2. At high temp, ductility
is high, so large strains
can be given.
Temp of working below
Trecryst.
At low temp, ductility is
low, large strains can not
be given. For large
dimensional changes,
intermediate annealing is
necessary.

23. Hot working Cold working
3. At high temp, flow
stress is low, required
forming loads are low. No
need for presses with high
capacity.
4. Need for high temp
facilities increases cost.
For reactive metals inert
atmosphere is required.
Flow stress is high,
required forming loads
are high. Need for high
capacity presses.
Need for intermediate
annealing facilities for
large strains.

24. Hot working Cold working
5. Automation is difficult.
6. Surface oxidation problem
leads to poor surface finish,
wastage of material. Defects
like rolled in oxides occur.
7. Poor dimensional accuracy
due to large strains and
thermal
expansion/contractions.
8. Structure and properties are
not uniform.
Automation is easy.
No oxidation problems, good
surface finish, less wastage of
material.
Better dimensional accuracy
due to small strains and good
control of the process.
Better uniformity of
properties.

25. Metal Forming System
• The deformation-processing situation in any
metal forming is best viewed as a total
system.

27. Important considerations
1. Properties of material: Flow stress and its
dependence on strain, strain rate and
temperature.
2. Deformation zone: Distribution of stress, strain
and particle velocities, overall pressure required
to perform the operations.
Applied forces, metallurgical phenomena such as
strain hardening, recrystallisation etc. are
important.

28. Important considerations
3. Friction and lubrication: Contact between
workplace and tools, type of friction,
mechanism of lubrication
4. Heat Flow: Heat transfer during deformation.
5. Tool wear and tool life: Friction, lubrication,
forces applied, tool material, surface quality
of deforming material.
6. Product: Surface finish, dimensional accuracy,
properties.

29. Analysis of metal forming processes
Principal uses of analytical studies of metal
forming processes:
1. Determination of the forces required for producing
the desired deformation.
2. Selection and design of the equipment/tools for a
particular job.
3. Prediction and prevention of defects during
forming.
4. Prediction of the limiting deformation at which
fracture will occur.

31. Effect of temperature on flow stress

32. Effect of temperature on flow stress
• Above a certain temperature, strain
hardening is nullified by softening
mechanisms like recovery and
recrystallisation that occur simultaneously
with deformation (dynamic
recrystallization).
• Flow stress decreases with temperature and
above recrystallisation temperature, flow
stress remains almost constant as the
deformation proceeds.