Auther Asim

2. Group Member
ASIM ASHFAQ
BSME-01113024

3. SUPER PLASTIC FORMING
EXPLOSIVE FORMING

4. SUPER PLASTIC FORMING

5. INTRODUCTION
Super plastic Forming is a metalworking process for
forming sheet metal. It works upon the theory of super
plasticity, which means that ” capability that some
materials have to undergo large uniform elongation
prior to necking and fracture tension”.
Super plastic forming (SPF) of sheet metal has been
used to produce very complex shapes and integrated
structures that are often lighter and stronger than the
assemblies they have to replace.
Titanium alloys and alloys of zinc-aluminum; when
heated , they can elongate to many times their original
length.

6. Some other materials which shows “superplasticity” are:
1. Titanium alloys
2. Aluminum alloys
3. Bismuth-tin alloys
4. Zinc-aluminum alloys
5. Stainless steel
6. Aluminum-lithium alloys

7. CONSTRUCTION

8. • PROCESS
• The process typically conducted at high temperature and under
controlled strain rate, can give a ten-fold increase in elongation
compared to conventional room temperature processes.
Components are formed by applying gas pressure between one or
more sheets and a die surface, causing the sheets to stretch and fill
the die cavity. Specific alloys of titanium, stainless steel, and
aluminum are commercially available with the fine-grained
microstructure and strain rate sensitivity of flow stress
that are necessary for Super plastic deformation.
• SPF can produce parts that are impossible to form using
conventional techniques. During the SPF process, the material is
heated to the SPF temperature within a sealed die. Inert gas
pressure is then applied, at a controlled rate forcing the material to
take the shape of the die pattern. Super plastic alloys can be
stretched at higher temperatures by several times of their initial
length without breaking.

9. EXAMPLES
 Construction of fuel Tanks
 Muddy Guards of Motorcars
ADVANTAGES
• The finished product has excellent precision and a fine
surface finish.
• Products can also be made larger to eliminate
assemblies or reduce weight, which is critical in
aerospace applications.
• Lower strength required and less tooling costs.

10. LIMITATIONS
• The biggest disadvantage is its slow forming rate.
• Materials must not be superplastic at Lower
temperatures.
• It is usually used on lower volume products.

11. APPLICATION IN PAKISTAN
Company: Super Plastic Doors & Windows
Address: Suit #11,1st Floor, Fareed Plaza, 65 Shadman
Market, Lahore, Punjab, Pakistan

12. EXPLOSIVE FORMING

13. DEFINITION
“Shaping metal parts in dies by using an explosive
charge to generate forming pressure.”
OR
“The shaping or modifying of metals by means of
explosions.”

14. VARIOUS TECHNIQUES
Explosive Forming Operations can be divided into
two groups, depending on the position of the explosive
charge relative to the work piece.
1. Stand Off Method
2. Contact Method

15. STAND OFF MATHOD
In this method metal plate is placed over a die,
with the intervening space evacuated by a vacuum
pump, then whole assembly is placed underwater and
explosive material is placed at an appropriate height
above the plate. For complicated shapes, a segmented
die can be used.
intervene: become involved

16. CONTACT MATHOD
In this method, the explosive charge is held in direct
contact with the work piece while the detonation is
initiated. The detonation produces interface pressures
on the surface of the metal up to several million psi.

19. PROCESS
The rapid change in explosive in to gas produce a
shock wave. The pressure of this shock wave is sufficient
to form metal sheet.
The peak pressure , p , due to explosion, generated in
water, is given by expression
p = k(((w)^1/2)/R)^a
Where P is in psi. K is the constant depends on the type of
explosive. W is the weight of Explosive in pounds. R is
the distance of explosive from the work piece and a is
the constant.

20. EXAMPLE

21. OTHER EXAMPLES
Rocket engine nozzle Space shuttle skin

22. ADVANTAGES
o It can simulate a variety of other conventional metal
forming techniques such as stamp- or press-forming and
spin-forming in a single operation.
o Explosive hydro-forming can efficiently form large parts
– up to 4’ square or 10’ in diameter.
o It is particularly suitable for short production runs of a
large parts such as occurs in aerospace applications.
o It Maintains precise tolerances and Eliminates costly
welds.

23. DISADVANTAGES
1. Low tooling costs, but high labor cost.
2. Suitable for low-quantity production.
3. Due to shock waves and spillage of water it is not
suitable to carry out indoor.
4. It should be done in open air.

24. COMPARISON
EXPLOSIVE FORMING SUPERPLASTIC FORMING
• In Explosive forming an • In super plastic forming
explosive charge is used punch or press is used to
instead of a punch or press. form metal sheet forming.
• It can be use for large size of • It can be only used for
metal sheets.
limited die design.
• No preheating required
before the explosive forming
• High production cost.
• Less production cost. • It can be used for definite
• Any product size, shape and
shape, size and sheet
sheet thickness is possible. thickness .