Centrifugal casting is a manufacturing process that uses centrifugal force to cast thin-walled cylinders and other rotationally symmetric shapes. In industrial centrifugal casting, a rotating mold is filled with molten metal which is thrown against the mold walls by centrifugal force and solidifies. This allows for precise control of material properties. Centrifugal casting for silversmithing involves pouring molten metal into a small spinning mold to fill fine details. Common applications include pipes, cylinders, and glass objects like marbles.

1. CENTRIFUGAL CASTING
a metallurgical manufacturing process by casting.

2. INTRODUCTION

3. Centrifugal casting
Has two types:
Industrial – that refers on an industrial scale.
Silversmithing – for smaller scale.

4. INDUSTRIAL
A type of centrifugal casting.

5. Centrifugal Casting (Industrial)
Centrifugal casting
also known as rotocasting, is a casting technique that is
typically used to cast thin-walled cylinders. It is noted for
the high quality of the results attainable, particularly for
precise control of their metallurgy and crystal structure.
Unlike most other casting techniques, centrifugal casting is
chiefly used to manufacture stock materials in standard
sizes for further machining, rather than shaped parts
tailored to a particular end-use.

6. Centrifugal Casting (Industrial)
Centrifugal casting
Centrifugal casting was the invention of Alfred Krupp,
who used it to manufacture cast steel tyres for railway
wheels in 1852.

7. PROCESS
How is centrifugal casting done?

8. Centrifugal Casting (Industrial)
Process
In centrifugal casting, a permanent mold is rotated
continuously about its axis at high speeds (300 to
3000 rpm) as the molten metal is poured. The
molten metal is centrifugally thrown towards the
inside mold wall, where it solidifies after cooling.

9. Centrifugal Casting (Industrial)
Process
The casting is usually a fine-grained casting with a
very fine-grained outer diameter, owing to chilling
against the mould surface. Impurities and
inclusions are thrown to the surface of the inside
diameter, which can be machined away.

10. Centrifugal Casting (Industrial)
Process
Casting machines may be either horizontal or
vertical-axis. Horizontal axis machines are
preferred for long, thin cylinders, vertical machines
for rings.

11. Centrifugal Casting (Industrial)
Process
Most castings are solidified from the outside first.
This may be used to encourage directional
solidification of the casting, and thus give useful
metallurgical properties to it. Often the inner and
outer layers are discarded and only the
intermediary columnar zone is used.

12. FEATURES
What are the prominent part of centrifugal casting?

13. Centrifugal Casting (Industrial)
Features of centrifugal casting:
Castings can be made in almost any length,
thickness and diameter.
Different wall thicknesses can be produced from
the same size mold.

14. Centrifugal Casting (Industrial)
Features of centrifugal casting:
Eliminates the need for cores.
Resistant to atmospheric corrosion, a typical
situation with pipes.

15. Centrifugal Casting (Industrial)
Features of centrifugal casting:
Mechanical properties of centrifugal castings are
excellent.
Only cylindrical shapes can be produced with this
process.

16. Centrifugal Casting (Industrial)
Features of centrifugal casting:
Size limits are up to 3 m (10 feet) diameter and 15
m (50 feet) length.
Wall thickness range from 2.5 mm to 125 mm (0.1
- 5.0 in).

17. Centrifugal Casting (Industrial)
Features of centrifugal casting:
Tolerance limit: on the OD can be 2.5 mm (0.1 in)
on the ID can be 3.8 mm (0.15 in).
Surface finish ranges from 2.5 mm to 12.5 mm (0.1
- 0.5 in) rms.

18. BENEFITS
What are the helpful results of centrifugal casting?

19. Centrifugal Casting (Industrial)
Benefits:
Cylinders and shapes with rotational symmetry are
most commonly cast by this technique.

20. Centrifugal Casting (Industrial)
Benefits:
Thin-walled cylinders are difficult to cast by other
means, but centrifugal casting is particularly suited
to them. To the rotation radius, these are
effectively shallow flat castings and are thus
simple.

21. Centrifugal Casting (Industrial)
Benefits:
Centrifugal casting is also applied to the casting of
disk and cylindrical shaped objects such as railway
carriage wheels or machine fittings where the
grain, flow, and balance are important to the
durability and utility of the finished product.

22. Centrifugal Casting (Industrial)
Benefits:
Providing that the shape is relatively constant in
radius, noncircular shapes may also be cast.

23. MATERIALS
What types of materials can be casted by centrifugal casting?

24. Centrifugal Casting (Industrial)
Typical materials that can be cast with this
process are:
Iron
Steel
stainless steels
Glass
alloys of aluminum, copper and nickel.
(Note: Two materials can be cast together by introducing a
second material during the process.)

25. APPLICATION
Where can we apply centrifugal casting?

26. Centrifugal Casting (Industrial)
Typical parts made by this process are:
Pipes
Boilers
pressure vessels
Flywheels
cylinder liners
other parts that are axi-symmetric
sleeve valves for piston engines

27. SILVERSMITHING
A type of centrifugal casting.

28. Centrifugal Casting (Silversmithing)
Centrifugal casting in silversmithing is a
casting technique where a small mould is
poured, then spun on the end of an arm.
The centrifugal force thus generated
encourages a successful pour.

29. PROCESS
How is centrifugal casting done?

30. Centrifugal Casting (Silversmithing)
Process:
Centrifugal casting, or centrifuging, is used as a means
of casting small, detailed parts or jewelry.
An articulated arm is free to spin around a vertical
axle, which is driven by an electric motor or a spring.

31. Centrifugal Casting (Silversmithing)
Process:
The entire mechanism is enclosed in a tub or drum to
contain hot metal should the mold break or an excess
of metal be used.
Single use molds are prepared using the lost wax
method.

32. Centrifugal Casting (Silversmithing)
Process:
A small amount of metal in a crucible (a sort of
ceramic pan) next to the mold is heated with a torch.
When the metal is molten the arm is released, forcing
(by centrifugal force) the metal into the mold.

33. Centrifugal Casting (Silversmithing)
Process:
The high forces imposed on the metal overcome the
viscosity, resulting in a finely detailed workpiece. For
casting of small parts using poured hot metal, a disk
shaped mold is contained within a rotating drum, and
molten metal is poured into the center.

34. PROCESS (GLASS)
Specialized for glass.

35. Centrifugal Casting (Silversmithing)
Process (Glass):
The technique is known in the glass industry as
"spinning".
The centrifugal force pushes the molten glass against
the mold wall, where it solidifies.

36. Centrifugal Casting (Silversmithing)
Process (Glass):
This cooling process takes anywhere between 16 to 72
hours depending on the impurities or volume of
material.
Typical products made using this process are television
picture tubes and missile nose cones.

37. APPLICATION
Where can we apply centrifugal casting?

38. Centrifugal Casting (Silversmithing)
Application:
Centrifugal casting is commonly used to shape
glass into spherical objects such as marbles.

39. MACHINERY
Machines involved in centrifugal casting.

40. Centrifugal Casting (Silversmithing)
Machinery:
Many machines are available which can perform
centrifugal casting, and they are relatively simple to
construct. All that is required is an arm which rotates
with an adequate amount of centrifugal force, a
container on the end of said arm to hold both a mold
and the material to be cast into the mold.

41. VIDEO PRESENTATION
A summary of our report

43. THE END