The short presentation gives insights to some die casting process, its principles, applications and some industrial use. It also includes different die casting methods.

1. DIE CASTING PROCESS:
PRINCIPLES, APPLICATIONS
AND INDUSTRIAL USE
MINI PROJECT(GROUP11)
ADVANCEDMANUFACTURINGPROCESS
ARSH SRIVASTAVA (17-12-093)
SAMA YASHWANTH REDDY (17-12-094)
MAYURJYOTI NEOG (17-12-095)
6th Semester
Mechanical Engineering Department, NIT Silchar

2. CASTING: Casting is an engineering manufacturing process generally used for
mass production in which materials in a molten state are poured into a mold
where they solidify.
DIE CASTING : Die casting is an automated casting process in which the liquid
melt is pressed into a mold under high pressure (150 to 1200 bar) and at a high
filling speed (up to 540 km/h). . It is especially suited for a large quantity of
small- to medium-sized castings, which is why die casting produces more
castings than any other casting process. Die castings are characterized by a very
good surface finish and dimensional accuracy with consistency.

3. DIE CASTING ALLOYS
ALUMINIUM: Aluminium is one of the most important materials with a share of more than 80 %. It is
often alloyed with copper or silicon. Aluminium is used to create components with thin walls and
complex shapes. Aluminium is also beneficial in components that will face exposure to thermal or
electrical energy.
COPPER: Many of these alloys are quite durable, making them an effective choice for mechanical
products. Due to copper’s very high resistance to corrosion, it is often used to create plumbing and
electrical material.
ZINC: Alloyed with aluminium to further improve these qualities. Valuable in the manufacture of
products that require high precision and sturdiness, such as connectors and gears. Easiest metal to
cast.
MAGNESIUM: Magnesium has a high strength-to-weight ratio and it is useful for die-casting
operations that require thin-structured walls and close precision.
LEAD and TIN are also used because of its high density and extremely closed dimensional
accuracy.

4. DIE CASTING MOLDS
The mold, generally called a die is made of two halves, of which one is fixed and other is
moving.
Before casting sufficient amount of lubricant is applied and then the molten metal is entered
the cavity at high pressure. The metal is held at high pressure till solidification of the cast
product.
 The most important material properties for the molds are thermal shock resistance,
softening at elevated temperature, hardenability, machinability, heat checking resistance,
weldability and cost.
The dies used in die casting are usually made out of hardened steel to withstand the high
heat.
the dies are very expensive but several tens of thousands to over a million castings can be
produced with just one of them.

5. DIE CASTING PROCESS CYCLE
CLAMPING: The first step in die-casting is the preparation and clamping of both halves of the
die. Before clamping, each of the die halves is cleaned and lubricated properly.
INJECTION: Molten metal, maintained at a set temperature is transferred to a chamber and
then injected to the die at high pressure.
 COOLING: When the molten metal enters the die cavity, it will start to cool and solidify. When
the complete cavity of the die is filled and the metal solidifies, the casting is formed. The die will
not be opened before the specified cooling time.
EJECTION: After cooling time has passed, the die halves are opened and an ejection
mechanism pushes the casting out of the die cavity.
TRIMMING: While cooling, the material in the channels of the die attach to the casting. This
metal, together with any flash, should be trimmed from the casting.
The total cycle time of die casting containing these steps is very short, typically between 2
seconds and 1 minute.

6. LUBRICANTS
It is important in die casting to incorporate a release agent to ensure that the product ejects from
the die effortlessly and free of defects. So, lubricants are used.
They serve as die casting release agents.
. Lubricants also allow for a hotter die surface, making the finished part more paintable and
better protected against soldering of the die.
Lubricants also resolve some casting related issues like porosity, in-cavity build-up, fish eyes,
cold shut etc.
Water-based lubricants are the most used type of lubricant, because of health, environmental,
and safety reasons.
 Some commonly used lubricants are diesel fuel, kerosene, water-in-oil and oil- in-water
emulsion, water etc.
. Some die casting companies are moving toward dry lubricants as wet lubricants can eventually
end up diluting local waterways.

7. TYPES OF DIE CASTING
Die casting is of two types
1.Gravity die casting
2.Pressure die casting

8. 1.GRAVITY DIE CASTING
→In this die casting process the molten metal enters into
the metallic mould by virtue of gravity.
→In this process both the moulds are closed first and
molten metal is injected into cavity by using spray nozzle.
→After the solidification of molten metal moulds are
moved apart and the metal is ejected.
→A hydraulic cylinder is used to operate
the movable mould.

9. 2.PRESSURE DIE CASTING
→In this die casting process molten meal enters into metallic mould by virtue
of applied external pressure
→It is of two types
a. cold chamber pressure die casting
b. hot chamber pressure die casting

10. A. Cold chamber pressure die casting
→In this casting process the furnace in which molten metal is made is
separate from the machine.
→In this process dies are closed and molten metal is
squeezed into the cavity by the application of external
pressure.
→After the solidification of molten metal dies are moved
apart and the casting is ejected from mould using ejector pins
and the cycle repeats.
→External pressure is applied on molten metal by using
plunger mechanism (Ram).

11. B. Hot chamber die casting process
→In this casting process the furnace in which molten metal is made is integral
part of machine.
→It is classified into two types based on the injection type:
1.Gooseneck air injection type
2.submerged plunger type

12. →There are also variations in the pressure die casting including
•Low pressure die casting
•Vacuum die casting
•Squeeze die casting
•Semi solid die casting

13. INDUSTRIAL APPLICATIONS
• Porosity-controlled, precision die castings are used in valve bodies for marine
power steering and industrial pumps, commercial air compressors.
• Suitable process for making zinc commercial door handles and industrial lighting
fixtures.
• Die cast components are manufactured for the automotive industry (cylinder
heads, valve blocks etc).
• Other industries which uses die cast parts are : aerospace, domestic appliances,
furniture etc.

14. ADVANTAGES OF DIE CASTING
• Die casting produces parts that are durable and dimensionally stable, while
maintaining close tolerances. They are also heat resistant.
• Die cast parts are stronger than plastic injection moldings having the same
dimensions.
• Die castings do not consist of separate parts welded or fastened together, the
strength is that of the alloy rather than the joining process.
• Die castings provide integral fastening elements, such as bosses and studs.
• Die casting provides complex shapes within closer tolerances than many other
mass production processes.

15. LIMITATIONS OF DIE CASTING
Main disadvantage is the very high capital cost. Both the casting equipment required
and the dies and related components are very costly, as compared to most other
casting processes.
Other drawbacks are as follows :
•Not applicable for high melting point metals and alloys (eg. steels).
•The cost of machines, dies and other equipment used is high.
•It’s not cheap to start with small quantity production.
•Special precautions are necessary for evacuation of air from die cavity, otherwise
cause porosity.
•It’s impossible to get a die casting prototype when product development process.
•Too long lead time

16. CONCLUSION
To recap, die casting is a casting
process used in the manufacturing
industry to create objects using
pressurized molten metal. The metal
or alloy for that matter is heated and
then forced into a mold cavity. As the
molten metal cools, it hardens. The
solidified casting can then be removed
from the mold cavity.