This file was made for a class presentation project.It was prepared by me and presented by me and my group-mates.

1. Chittagong University of Engineering &
Technology
Department of Mechanical Engineering
Submitted to:
Ratan Kumar Das
Lecturer,Dept. Of ME
CUET

2. •
Study of Powder metallurgy, Plastics
molding & press mechanism.

4. DEFINITION:
• Powder metallurgy may defined as, “the art and science of
producing metal powders and utilizing them to make
serviceable objects.”
OR
• It may also be defined as “material processing technique
used to consolidate particulate matter i.e. powders both
metal and/or non-metals.”

5. • First developed in Persia around 2500 BC
• Africans used the technique 1000 BC
• Incas used this process 400 years ago
• Modern use in Edison’s tungsten filament by
Coolidge in 1900s
• Now being used everywhere

6. • Provides controlled porosity for
self-lubrication or filtration.
• Facilitates manufacture of
complex or unique shapes which
would be impractical or
impossible with other
metalworking processes.
• Suited to moderate-to high
volume component production
requirements.
• Offers long-term performance
reliability in critical applications.
• Cost effective.
• Eliminates or minimizes machining.
• Eliminates or minimizes scrap loses.
• Maintains close dimensional
tolerances.
• Permits a wide variety of alloy
systems.
• Produces good surface finishes.
• Provides materials which may be
heat-treated for increased strength
or increased wear resistance.

7. • Automobile industry
• Abrasives
• Electric and magnetic devices
• Medical and dental
• Welding

9. •Powder production
•Blending
•Compaction
•Sintering
•Secondary or finishing operations.

11. •Atomization
• Chemical reduction
•Electrolytic techniques

12. Blending means agitation of powder for
homogenizing the particle sizes.

13. After blending,
the powders are
placed in a die
and compacted
by pushing a
punch in under
pressure. The
dies are usually
made of tungsten
carbide to reduce
wear of the die.

14. This is the important
step in PM process. The
green compacts are
heated in a muffle type
furnace in a controlled
atmosphere.

15. • Repressing
• Coining
• Sizing
• Machining
• Forging
• Heat treating
• Steam treating
• Plating

16. • Heat treating
• Steam treating
• Plating
• Joining
• Impregnation
• Infiltrations

17. • Shape of the compact must be simple and
uniform
• Provision must be made for the hiccup of the
part
• Wide tolerances should be used whenever
possible

18. • It is a technique for making parts from high melting
point refractory metals
• High production rate
• Good dimensional control
• Wide range of composition for obtaining special
mechanical and physical properties

19. • Competitive with casting and forging
• High initial cost
• Economical for quantities over 10,000 pieces
• Reduces or eliminates scraps

20. • High cost
• Tooling cost for short production run
• Limitation on part size and shape
• Variation in metal density and mechanical
properties.
• Expensive Raw Materials

22. DEFINITION:
Plastic moulding is the process of shaping plastic
using a rigid frame or mould. The technique allows
for the creation of objects of all shapes and sizes
with huge design flexibility for both simple and highly
complex designs.

23. • Since the invention of plastic by Alexander Parkes in
1862 people tried to use it. But in 1865 John Wyatt
successfully done it
• Since 1907 Bakelite was used
• Rayon was used since 1891
• Cellophane was invented in 1913
• Nylon was first used in 1920
• Polyvinylchloride (PVC) was invented in 1933
• People started using Teflon in 1938
• Polyethylene was developed in 1933
• And many more types are continuously being discovered

25. • Fast Production
• Material and Colour Flexibility
• Labour Costs Low
• Design Flexibility
• Low Waste

26. •Thermoplastics
•Thermosetting

27. • Rotational Moulding
• Injection Moulding
• Blow Moulding
• Compression Moulding
• Extrusion Moulding

28. • Mould charging
• Rotation(heating and fusion
combined)
• Cooling
• Product Demolding

29. • Apply force
• Inject plastic through a heated piston
• Softened plastic through a nozzle in am water
cooled die

32. • A tubular piece of
plastic is used
which is placed
between two mould
• Air is injected in
parison and heated
and pressurized
from outside
• After removing it is
cooled down

33. • Preheated polymer is placed in a die
• Heat and pressure is controlled throughout the
process

34. • Chamber is rotated and kept heated
• It is fed by plastic
• Cooled in extrusion die

35. • High initial tooling cost
• Part design restriction
• Difficulty in accuracy
• Cannot be used for short production runs

37. DEFINITION:
Press mechanism is a process where we use a
machine tool that changes the shape of a work
piece by the application of pressure. Press
mechanism may be defined as higher level of
compaction process.

38. • Development of steam hammer over the old
hammering process
• James Watt invented steam hammer 1st at 1784
• James Nasmyth developed the old steam hammer in
1840
• Revolutionized and first industrially used by
Bethlehem RON company in 1900’s
• Since then now many press machines are being
used based on hydraulics and servo mechanism

39. • Hydraulic press
• Mechanical press
• Pneumatic press

40. • Consists of two parts
• Upper part is a piston(built by
hydraulic mechanism) acts as a
pump
• Lower part helps to generate
mechanical force and works as a
bench
• It depends on Pascal’s Law

41. • Rotational force of machine is
transferred into translation
force
• The mechanical energy comes
from motor
• Speed and Magnitude can be
controlled by controlling the
power of the strokes
• Mainly used in forging
manufacture and sheet metal
working

42. • Pneumatics means breath
.So pressurized air is used
for creating press
• Controlled by manual or
automatic valve
• Consists of three parts
-compressor
-cylinder
- air motor

43. •Pivot drive
•Synchronous drive
•Skid steer drive
•Car type drive

44. • Two motors are used in this
process
• One is needed to rotate the chain
round the platform
• And the other is used to raise the
platform

45. •It is a system of motors
which provides
synchronous speed and
rotation to entire system
•One set of turns the wheel
and the other drives the
wheel
•Two sets can be
mechanically coupled as
they move in the same
direction with same speed

46. •Here two wheels are use and each have
different speed and control
•Wheels typically doesn’t have separate
driving mechanism
•The machine turns by skidding power or
dragging its fixed orientation

47. •It has separate pair of
driving wheel and steering
wheel
•Translation and rotation
speed are separate and
independent of each other
•But driving and steering are
interlinked so special path
and planning is necessary

48. • Light sensors may be
used to keep operator
from danger
• Should be controlled
carefully
• Goggles and other
precautions must be take

49. Chowdhury MD. Adib Zawad(1303123)
Joy Datta(1303125)
Shahariar Hossain(1303128)
Tansir ul Islam(1303129)
SAMA-E-SHAN (1303130)
Laxman Chandra(1203003)
Abu Bakkar Sikder(1203072)