Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. this process is must in many industries for production.

1. NAME: KEMKAR JAIMIN AJITKUMAR
EN. NO.: 160123119014
SEM. & BATCH: 4TH – D2
SUBJECT:
MANUFACTURING PROCESSES (2141908)
GUIDED BY:

2. • INTRODUCTION OF CASTING
• SELECTION OF CASTING PROCESS
• REQUIREMENTS OF CASTING
• TYPES OF CASTING
• STEPS OF CASTING

3. • CASTING:
• MANUFACTURING OF A MACHINE PARTS BY HEATING A METAL OR ALLOY ABOVE ITS
MELTING POINT AND POURING THE LIQUID METAL/ALLOY IN A CAVITY
APPROXIMATELY OF SAME SHAPE AND SIZE AS THE MACHINE PART IS CALLD CASTING
PROCESS.
• AFTER THE LIQUID METAL COOLS AND SOLIDIFIES, IT ACQUIRES THE SHAPE
AND SIZE OF CAVITY AND RESEMBLES THE FINISHED PRODUCT REQUIRED.
• THE DEPARTMENT OF THE WORKSHOP WHERE CASTINGS ARE MADE IS
CALLED FOUNDRY.

4. • Quantity to be produce
• Requirement of the product in terms of surface finish, accuracy,
complexity, etc.
• Physical properties of the material
• Process capability to meet the requirement
• Initial investment required and operational costs

5. 1. PREPARATION OF PATTERN
2. PREPARATION OF MOULD WITH THE HELP OF THE PATTERN
3. MELTING OF METAL OR ALLOY IN A FURNACE
4. POURING OF MOLTEN METAL INTO MOULD CAVITY
5. BREAKING THE MOULD TO RETRIVE THE CASTING
6. CLEANING THE CASTING AND CUTTING OFF RISERS, RUNNERS ETC.
(FETTLING)
7. INSPECTION OF CASTING

6. • Patterns are replicas of the casting required. It is similar in shape and size to
the final product, but not exactly.
• Shrinkage allowance
• Machining allowance
• Draft allowance
• Distortion allowance
• Shake or rapping allowance

7. Solid or single piece pattern
Split pattern
Loose piece pattern
Match plate pattern
Gated pattern
Wood
Metal
Plastic
polystyrene

8. • Mould making is the very important process In casting. A very fine Mould reflects on the
finishing of final casted product.
Green sand mould
Skin dry mould
Dry mould
Core
Core print
Gates
Runners
Risers

9. • For casting, metal has to be heated above its melting point. The heating is
done in a furnace.
• Depending upon the fuel used, the furnaces may be classified as electric, oil
fired or coal fired etc.
• Where metal free from any impurities is required, electric furnaces are used.
• In coal fired and coal fired furnaces, the flame plays upon the hot metal and
the molten metal picks up impurities by coming in contact with flames.
• for non-ferrous metals and alloys, oil fired crucible furnaces are used. The
metal is placed in large graphite crucibles and heated on the outside surface
of crucibles, so that flames don’t come in actual contact with metal.

10. • Ladles which pour the molten metal from beneath the surface are used
• The two main consideration during pouring are the temperature and pouring
rate
• Fluidity of molten metal is more at higher temperature but it results into
more amount of dissolved gases and high temperature also damage the
mould walls and results into poor surface quality of the casting
• To control the amount of dissolved gases low, the temperature should not
be in superheated range
• The pouring rate should be such that solidification does not start and the
cavity is completely filled without eroding mould surface and undue
turbulence.

11. • Casting is taken out of the mould by shaking and the Molding sand is recycled often with
suitable additions.
• Sometimes castings are heat treated to achieve better mechanical properties.
• The remaining sand, some of which may be embedded in the casting, is removed by
means of Shot blasting.
• The excess material in the form of sprue, runners, gates etc., along with the flashes formed
due to flow of molten metal into the gaps is broken manually in case of brittle casting or
removed by sawing and grinding in case of ductile grinding.
• The entire casting is then cleaned by either shot blasting or chemical pickling.

12. Most surface defects can be seen
The casting is filled with pressurized air after closing all the openings
E.g. gear boxes, pressure vessels, look for leaks by submerging in special liquids
Pressurized oil can also be used in some cases
Usually x-rays or g rays
x-ray method is used for voids, on metallic inclusions, porosity, cracks
Defects appear darker than surrounding

13. Ultrasound across the casting
Sound transmitted across homogenous metals
However discontinuities reflect sound back.
Not good for cast iron
To detect invisible surface defects in non magnetic castings
A dye of fluorescent material is sprayed or applied near the surface. The surface is then
wiped and viewed in darkness
Cracks will be visible
Induce magnetic field through section under inspection
Powdered Ferro-magnetic magnetic material is spread onto the surface
Voids or cracks result in abrupt changes in permeability of material – leads to leakage
in magnetic field
Particles concentrate on the disrupted field or on the crack.

14. • Book:
• Production technology
• Manufacturing engineering