This PPT Base On Metal Forming Process

1. Metal Forming Course
• (a) Ideal deformation of
a solid cylindrical
specimen compressed
between flat frictionless
dies.
• (b) Deformation in
upsetting with friction at
the die-workpiece
interfaces.
Open-Die Forging

2. Metal Forming Course
Impression (Closed) Die Forging
• Schematic illustration of stages in impression-die forging. Note
the formation of flash, or excess material that is subsequently
trimmed off.

3. Metal Forming Course
Load-Stroke Curve in Closed-Die Forging
• Typical load-stroke
curve for closed-die
forging. Note the
sharp increase in load
after the flash begins
to form. In hot-forging
operations, the flash
requires high levels of
stress, because it is
thin-that is, it has a
small h-and cooler
than the bulk of the
forging.

4. Metal Forming Course
Heading
• Forging heads on
fasteners such as bolts
and rivets. These
processes are called
heading.
Piercing Operations
• Examples of piercing
operations.

5. Metal Forming Course
Cogging Operation
• Schematic illustration of a cogging operation on a rectangular
bar. With simple tools, the thickness and cross-section of a bar
can be reduced by multiple cogging operations. Note the
barreling after cogging. Blacksmiths use a similar procedure to
reduce the thickness of parts in small increments by heating the
workpiece and hammering it numerous times.

6. Metal Forming Course
Forging A Connecting Rod
• Stages in forging a connecting rod for an internal combustion
engine. Note the amount of flash that is necessary to fill the die
cavities properly.

7. Metal Forming Course
Features Of A Forging Die
Hot-Forging Temperature Ranges
Metal °C Metal °C
Aluminum alloys
Copper alloys
Nickel alloys
400-450
625-950
870-1230
Alloy steels
Titanium alloys
Refractory alloys
925-1260
750-795
975-1650

8. Metal Forming Course
Presses Used In Metalworking
• Schematic illustration of various types of presses used in
metalworking. The choice of the press is an important factor in
the overall operation.

9. Metal Forming Course
Flat-And-Shape-
Rolling Processes

10. Metal Forming Course
Flat-Rolling Process
• Schematic illustration of the
flat-rolling process. A greater
volume of metal is formed by
rolling than by any other
metalworking process.
• Relative velocity distribution
between roll and strip surfaces.
Note the difference in the
direction of frictional forces. The
arrows represent the frictional
forces acting on the strip.

11. Metal Forming Course
Roll Bending and Workpiece Spreading
• (a) Bending of straight
cylindrical rolls because of the
roll force. (b) Bending of rolls,
ground with camber, that
produce a sheet of uniform
thickness during rolling.
•Increase in the width of a
strip (spreading) in flat
rolling.

12. Metal Forming Course
Defects In Flat Rolling
• Schematic illustration of typical defects in flat rolling: (a) wavy
edges; (b) zipper cracks in the center of strip; (c) edge cracks;
(d) alligatoring.

13. Metal Forming Course
Shape Rolling
• Stages in shape
rolling of an H-
section part.
Various other
structural
sections, such
as channels and
I-beams, are
also rolled by
this process.

14. Metal Forming Course
Ring-Rolling
• (a) Schematic illustration of a ring-rolling operation. Reducing
the thickness results in an increase in the part’s diameter. (b)
Examples of cross-sections that can be formed by ring rolling.

15. Metal Forming Course
Types Of Extrusion
• Types of
extrusion.
(a) direct;
(b) indirect;
(c) hydrostatic;
(d) impact.

16. Metal Forming Course
Extrusion
• Extrusion and examples
of products made by
sectioning off extrusions.
• Schematic illustration of three
different types of metal flow in
direct extrusion.

17. Metal Forming Course
Chevron Cracking
• (a) Deformation zone in extrusion, showing rigid and plastic
zones. Note that the plastic zones do not meet, leading to
chevron cracking. The same observations are also made in
drawing round bars through conical dies and drawing flat sheet
plate through wedge-shaped dies. (b) Chevron cracking in round
steel bars during extrusion. Unless the part is inspected
properly, such internal detects may remain undetected and
possibly cause failure of the part in service.

18. Metal Forming Course
Drawing
• Variables in drawing
round rod or wire.
• Variation in strain and flow stress
in the deformation zone in drawing.
Note that the strain increases
rapidly toward the exit. The reason
is that when the exit diameter is
zero, the true strain reaches infinity.
The point Ywire represents the yield
stress of the wire.

19. Metal Forming Course
Forming Processes For Rocket Casings
• The forming processes involves in the manufacture of solid
rocket casings for the U.S. Space Shuttle.

20. Metal Forming Course
The End