10 Types of Casting Patterns Explained

CASTING
 Department of mechanical Engineering
 PREC Loni.

WHAT IS PATTERN IN CASTING?
 Generally speaking, the pattern in casting is the
object for casting. Casting pattern shapes casting
mould, and the mould creates metal parts, so the
casting pattern is very crucial to the final parts.
Therefore, the casting parts designer should
consider more product details during the pattern
design phrase
 Making a casting pattern is not only shaping a
mould cavity, accurate dimensions, scientific
feeding system, and mould removing method
should also be considered.

MATERIALS OF CASTING PATTERN
 Your casting pattern materials should these properties:
 Lower cost and less weight: with the lower cost and less
weight you are easier to find the balanced point of costs and
returns.
 Resistance of water: choosing the material with resistance
of water protects your casting pattern from rusting. Casting
patterns with this kind of material will have a long lifetime
and produce high quality patterns.
 Durable: durable material provides a long lifetime of your
casting pattern, so you should consider the durable property
of the material before you choose casting pattern materials.
 Versatile: various industries need casting patterns to create
the casting process, so the versatile property of casting
pattern material is very important. It ensures the pattern can
be used in many kinds of industries, and repaired easier.

MATERIALS USED FOR PATTERN:
 Some key factors are in mind before choosing a
material for the pattern:
 The materials used in the pattern should be cheap
in cost and easily available in the market.
 The material should have a good surface finish.
 The material should have withstood high
temperatures and does not change its shape at
high temperatures.
 Generally, we use 5 different types of material to
make the patter and those are:
 Wood
 Metals
 Plaster of Paris
 Plastics

WOOD:
 As we all know woods are easily available, and the price is
quite low so it is satisfied us some basic criteria which I
mentioned above.
 Also, there are some advantages using wood in
pattern and those are:
 Wood is light in weight
 Easily Available in the market
 You can make any shape using wood
 Woods gives good surface finish
 However wood is attracted to moisture and sometimes it
can change shape on high temperature or after dry out
from moisture, this is an important con of using wood as a
pattern.
 Not only this reason woods are very week in strength, and
it wears out quickly due to its low resistance to sand

METALS:
 In metals, cast iron, brass, aluminum are generally used
in patterns. It gives smooth surface finish, this is the only
reason that metals are used in large production casting
workshops.
 These are some advantages of using Metal Pattern:
 Smooth surface finish can be obtained by metal patterns.
 Deformation is less.
 Closer dimensional tolerance.
 Although there are some disadvantages of using this
type of pattern like it is a little bit costlier, heavy,
sometimes rusting effect occurred on the surfaces of the
metals.

 Plaster of Paris:
 It is generally used if you need to set up the pattern quickly.
The main advantage of this pattern is it can easily cast into
intricate shapes.
 However, it is not for repetitive usages as it is fragile.
 Plastics:
 Different types of plastics are nowadays used in pattern
because of their lighter weight, strength, and dimensionally
stable and also for cheap in cost.
 Thermoplastics and polystyrene are commonly used for
making patterns, and Thermosetting plastics such as
phenolics and epoxies are also used in a pattern.
 There are few advantages of using pattern and those
are:
 Light in weight.
 Cheap in price.

WAX:
 A wax pattern used in the investment casting
process. By using this pattern we get a high degree
of accuracy and have an excellent surface finish.
 However it needs little care handling otherwise it
can be broken, and it is used in small casting.

TYPES OF PATTERN ALLOWANCES
 Other factors like the type of casting pattern and the properties
of casting metal should also consider. Therefore, there have
some casting pattern allowances you should pay attention to
during pattern making manufacturing process.
 Draft allowances: draft allowances creates a taper for
removing casting patter without any distortion. And the
accurate angle of taper depends on the type of mold and
surface, and the complexity of the casting pattern.
 Shrinkage allowance: usually the casting pattern has a bigger
size of the mold, because most metal material contracts when
it cools. The shrinkage allowance compensates for the cooling
shrink of metal, and the precise parameter of the allowance
depends on the metal material.
 Distortion allowance: casting patterns have a special design
for avoiding the expected cooling distortion. We call it a
distortion allowance.
 Machining allowance: excess material in the finishing stage
for compensating some loss materials.

CASTING VS.PATTERN
 The main difference between pattern and casting is
that a pattern is a tool while casting is a kind of
process.
 Casting: It is a kind of process that manufacturers
pour the molten metal into a mold, where the
material cools and solidifies. The final shape of
products was decided by the mold cavity, while the
shape of the mold should be considered, and that is
where the pattern appears.
 Pattern: Before you make a mold, you should
design a pattern firstly. The pattern is the primary
shape of the mold and finally, the product shapes
according to the pattern.

10 COMMONEST TYPES OF PATTERNS IN CASTING
 Single piece pattern
 two piece pattern
 gated pattern
 multi piece pattern
 match plate pattern
 skeleton pattern
 sweep pattern
 lose piece pattern
 cope and drag pattern,
 shell pattern.

SINGLE PIECE PATTERN
 Single piece pattern, also called solid pattern is the
lowest cost casting pattern. It is very suitable for
simple process, and small scale production and the
large casting manufacturers prefer it because this
kind of casting pattern make casting process just
needing simple shapes, flat surfaces like simple
rectangular blocks. One flat surface is used to
separate planes.

TWO-PIECE PATTERN
 Two-piece pattern also called split piece pattern is a common
casting pattern for intricate casting. This kind of pattern has
parting planes which may have flat or irregular surface, and
the exact position of the plane was decided by the shape of
the casting. There are two pieces of the split piece pattern.
One of the parts is molded in drag and another is molded in
cope. And the cope part always has dowel pins. With the
dowel pins, the two halves of split piece pattern can be
aligned.

MULTI PIECE PATTERN
 Multi piece pattern is a good solution for complex
designs which is hard to make. This kind of pattern
includes 3 or more pattern which helps you achieve
mold making.
Take the three-piece pattern as an example. The
pattern is made of the top, bottom, and middle
parts. The top part is cope, the bottom part drag,
and the middle parts are called as checkbox.

MATCH PLATE PATTERN
Match plate pattern has a metallic plate to divide the
cope and drag areas into the opposite face of the plate.
This kind of pattern nearly has no hard work and can
provide high output. It is widely used in the
manufacturing industry, and usually has an expensive
cost, precise casting and high yield. And this kind of
casting pattern is widely used in metal casting like
aluminum.

GATE PATTERN
 Gate pattern can consist of one or more patterns into a
molding pattern. It is designed for the mold which makes
multiple components at one casting process. The gates
are used to combine the different patterns, and runners to
create a flow way for the molten materials. When the
gates and runners have already attached, the patterns are
loosing. This kind of pattern is expensive, and it is usually
used for small castings.

SKELETON PATTERN
 Skeleton pattern is large in size, and it is a good choice
for the casting which has the simple size and shape.
This kind of casting pattern is expensive and not
versatile. It is not the best choice from the aspect of
economic, while is very efficient in extra sand removing.
If you want to use this casting pattern you should
highlight the wood frames when you casting. The
skeleton pattern is widely used in the industries of pit or
floor welding.

SWEEP PATTERN
Sweep pattern uses a wooden board with proper size to rotate along one
edge to shape the cavity. This kind of casting pattern creates a cavity in the
vertical direction and the base of it is attached with sand, and it also creates
casting in a very short time, and it has consisted of three parts: spindle,
base and sweep which also called wooden board.

LOOSE PIECE PATTERN
Loose piece pattern can help manufacturers remove one piece of solid
pattern which is above or below the parting plane of the mold. This kind of
pattern needs extra skilled labor work, so it is expensive casting pattern in
castings.

COPE AND DRAG PATTERN
Just like its name, cope and drag pattern has consisted of two
separate plates, and it has two parts which can be separately molded
on the molding box, and these parts create the cavity. This kind of
pattern has a bit similar with the two-piece pattern and is usually used
in large casting.

Shell pattern is a good choice to create hollow shaped structure. It
parts along the center and dowels the resultant halves.
The above is about 10 different types of patterns in the casting
process. Now, do you know what is casting and its types?

PROPERTIES OF MOULDING MATERIAL
 Moulding sand should possess the following 6 properties
 Porosity:-It is the ability of sand by which it allows the
gases to pass through it easily.
 Flowability:-The ability of moulding sand to behave like a
fluid when it is rammed is called flowability.
 Collapsibility:-The ability of the moulding sand to collapse
after solidification of the molten metal is called
collapsibility.
 Adhesiveness:-The ability of the sand particles to get stick
with another body is called adhesiveness.
 Cohesiveness or strength:-The ability of the sand particles
to stick with each other is called cohesiveness
 Refractoriness:-The ability of the moulding sand to
withstand the high temperature of the molten metal
without fusing into it is called refractoriness.

MOULDING MATERIALS
 Good casting can be determined by the pattern and the types
of molding sand used. One needs to understand the types of
molding sand used in casting in order to perfectly create
objects
 Types of molding sand used in casting
 1 Greensand:
 2 Dry sand:
 3 Facing sand:
 4 Core sand:
 5 Loam sand:
 6 Parting sand:
 7 Backing and floor sand:
 8 System sand:
 9 Molasses sand:

 Greensand:
 these types of molding sand are natural sand with enough moisture in
them. It contains clay of about 15 to 30%, 8% of water, and silica. The
clay and water act as binding materials that gives strength to the mold. it
is used only for simple and rough casting. It is used for both ferrous
and non-ferrous metal.
 Dry sand:
 This casting sand is obtained when the moisture from green sand is
removed. It used for large and heavy casting because the molding
sand offers greater strength, rigidity, and thermal stability to the casting.
 Facing sand:
 as the name implies, facing sand is used for facing the mold. it consists
of fresh silica sand and clay. That is, no used sand is added. It is used
directly next to the surface of the pattern. Facing casting sand must
have high refractoriness and strength because it comes in direct contact
with the hot molten metal. These types of molding sand give the mold a
very fine grain.
 Core sand:
 Core molding sand types contain silica sand mixed with core oil
(linseed oil, resin, and mineral oil) and other binding materials like
dextrin, cornflour, and sodium silicate. It is used for cores making and
has high compressive strength.

 Loam sand:
 Loam sand is an equal mixture of sand and clay with a sufficient amount
of water added to it. It is also used for large and heavy molding like
hoppers, turbine parts, etc.
 Parting sand:
 These types of molding sand are pure silica sand poured on the faces
of a pattern before molding. Parting sand is sprinkled on the pattern
before it is embedded in the molding sand. This casting sand is also
sprinkled on the contact surface of cope, drag, and cheek.
 Backing and floor sand:
 This casting sand is used to back up the facing sand and to fill the
volume of the box. It is also known as floor sand.
 System sand:
 This molding sand is applicable to mechanical heavy castings. It has
high strength, permeability, and refractoriness. System sand is used for
machine molding to fill the whole flask. Facing sand is not used in
this molding because cleaned and has special additives.
 Molasses sand:
 This molding sand is also used for core making and small casting of
intricate shapes. It contains molasses as its source of binding.

MOLDING
 Molding is the process of manufacturing by shaping liquid or pliable
raw material using a rigid frame called a mold or matrix. This itself
may have been made using a pattern or model of the final object. ...
The liquid hardens or sets inside the mold, adopting its shape.
A mold or mould is a hollowed-out block that is filled with a liquid or
pliable material such as plastic, glass, metal, or ceramic raw
material. A mold is the counterpart to a cast.
 Molding is a technique through which a material, often plastic, but
also metal, rubber, or powder mixtures is shaped on the outline of a
die or mold. There are many different techniques
for molding materials, just as there are many different applications for
each process.
 Moulding Boxes. ... Special purpose boxes are designed for use
in moulding systems where the demand of high
pressure moulding and high production rates (from a fully automated
system) require a box designed & machined to exacting tolerances.

STEPS FOR MAKING MOULD
1)place the wooden pattern in drag box on the moulding board
with parting surface in contact with the board.
2)Put the moulding sand in the drag and ram the sand uniformly in
the dragbox.
3)Turn the drag box and remove pattern and sprinkle parting sand
over the surface uniformly.
4)Prepare the cope box by placing the runner and riser pins in
proper position if require core also.
5)Place the cope box over the drag box.
6)Remove riser pins dust the surface of the mould with a coating
material ,let it dry.
7)The cope and drag the mould is now ready for pouring, now the
molten metal is poured inside the mould box through sprue hole .
8)Once the metal solidifies the molding box is seperated by dis
engaging the pins.

DIFFERENT TYPES OF MOULDS
 1.Ceramic Moulds
 2.Permanent Mould
 3.Multi Piece mould
 4.Die Casting
 5.Sand casting Mould
 6.Shell Mould
 7.plaster mould
 8.Graphite casting mould.

 1.Ceramic Moulds :-
 Ceramic slurry is poured over a relief pattern and left to
solidify, forming a cavity mould in the shape of the component to be
cast. Cope and drag parts are produced. Each ceramic part is
hardened by high temperature firing, then fitted together to make
one hollow mould in which to cast the molten metal.
 2.Permanent Mould:-Permanent mold casting is a metal casting
process that shares similarities to both sand casting and die casting.
As in sand casting, molten metal is poured into a mold which is
clamped shut until the material cools and solidifies into the desired
part shape. However, sand casting uses an expendable mold which
is destroyed after each cycle. Permanent mold casting, like die
casting, uses a metal mold (die) that is typically made from steel or
cast iron and can be reused for several thousand cycles. Because
the molten metal is poured into the die and not forcibly injected,
permanent mold casting is often referred to as gravity die casting.


TYPES OF MOULDING METHOD
 1)Bench Molding
 2)Floor Moulding
 3)Pit moulding
 4)Machine Moulding

3)PIT MOULDING
• It is used for very large casting work and done on the foundry floor.
 • A pit dug in a floor act as a lower flask [drag] and top flask [cope] is
placed over the pit.
 • The walls of the pit are brick-lined and Plastered with loam sand and
allowed to dry.
 • Sometimes pit bottom is rammed with 50-80 mm layer of coke to
improve permeability of mould.
 • Vent pipes are run from this layer to the surface.
 • Coke is covered with backing sand.

TYPES OF MOULDING MACHINES
 1)Jolt machine
 2)Squeeze machine
 3)Jolt and squeeze machine
 4)sand slinger machine

MOULDING MACHINES
 Jolt-squeeze machine

HAND MOULDING EQUIPMENTS
Hand riddle Shovel Rammers Sprue pin Strike off bar
Draw spike
Vent rod Lifter
Trowels
Slicks Smoothers Swab
Gate cutter

CORE
 Core: Used to produce Hallow Casting
eg. Holes, Recess, Projections, Internal Cavity.
 Coreprints: region added on Pattern to Locate and
Support Core in Mould.
 Characteristics of Core (Sand)
 •High Permeability to allow an Easy Escape to gases
formed.
 •High refractoriness to withstand high temperature of
molten metal
 •Smooth surface.
 •High collapsibility i.e. it should be able to disintegrate
quickly after the solidification of the metal is complete.

CORE
 Core is a sand shape or form which makes contour
of a casting for which no provision has been made
in the pattern for moulding.
 Core is an obstruction which when positioned in
the mould, does not permit the molten poured
metal to fill the space occupied by core hence
produce hollow casting.
 Core may be made up of sand,
plaster, metal or ceramics.
Fig. Core

FUNCTIONS OF CORE
 It provides a means of forming the main internal cavity for
hollow casting.
 It provides external undercut feature.
 It can be inserted to obtain deep recesses in the casting.
 It can be used to increase the strength of the mould.
 It can be used as a part of gating assembly.
 It can form a part of green sand mould and can also be used to
improve the mould surface.

STEPS INVOLVED IN CORE MAKING
1. Core sand preparation
2. Core making
 Small cores can be made manually in hand rammed core boxes.
 Cores on mass scale are rapidly produced on various core making
machines namely jolt machine, shell core machine, core blower, sand
slinger, core roll over machine and core extrusion machine.
3. Core baking
4. Finishing of cores
5. Setting the cores

Types of cores
 Horizontal Core
Usually in a cylindrical form laid horizontally in the
mold.
 Vertical core
The core is placed along a vertical axis in the mould

 Balance core
 Suitable when the casting has an opening only on
one side and only one coreprint is available on the
pattern.
 Cover Core
 •When the entire pattern is rammed in the drag and
the core is required to be suspended from the top of
the mold

 Hanging Core
•If the core hangs from the cope and does not have any
support at the bottom in the drag, it is referred to as a
hanging core
 Wing core
 When a hole or recess is to be obtained in the
casting either above or below the parting line.

MELTING PRACTICES AND FURNACES
 Cupolas Furnace
 Direct fuel-fired furnaces
 Crucible furnace
 Electric arc Furnace
 Induction furnace

CUPOLAS FURNACE
Cupola furnace is one of the furnace where we melt different types of
metal some are cast iron, some are maybe bronze.
The Cupola furnace works on the principle where we generate heat
from burning coke and when the temperature of the furnace is above
the melting point of the metal then the metal is melt.

MATERIAL:- BRONZE, BRASS ALLOYS,ZINC,ALUMINUM

GATING SYSTEM
Components
are
 Pouring
cups and
basins
 Sprue
 Runner
 Gates
 Riser, etc
Dec 2009, Dec 2010, May 2011,
May 2012

COMPONENTS OF GATING SYSTEM
 Pouring cups
 It is funnel shaped cup which forms the top portion of the sprue.
 It makes easier for the ladle or crucible operator to direct the flow
of metal from crucible to sprue.
 Pouring basins
 It acts as a reservoir for molten metal from which it moves
smoothly into the sprue.
 It prevents the slag from entering the mould cavity.
 It holds the slag and dirt, which floats on the top and allows only
the clean metal to enter into the sprue.

 Sprue
 It is the channel through which the molten metal is brought into
the parting plane where it enters the runner and gates.
 Sprue may be square or round and is generally tapered
downwards to avoid aspiration of air and metal damage.
 Rectangular sprue has less turbulence.
 Runner
 In large casting, molten metal is generally carried from the sprue
base to several gates around the cavity through a passage called
as runner.
 Location of runner depends upon the shape of casting.
 It should be streamlined to avoid aspiration and turbulence.

 Gates
 A gate is a channel which connects runner with the mould cavity
through which molten metal enters into the cavity.
 The location and size of gates are so arranged that they can fill
casting with consistent rate.
 Ingate is the end of the gate where it joins the mould cavity.
 Gating ratio is the ratio of sprue base area to the runner area and
the total ingate area (As:Ar:Ag).
 Choke is that part of gating system which has the smallest
cross-sectional area. It controls the flow rate of metal and to hold
back slag, foreign particles, etc.

 Riser or feeder head
 A riser or feeder is a passage of sand made in the cope to permit
the molten metal to rise above the highest point in the casting
after filling.
 This metal in the riser compensates the shrinkages as the
casting solidifies.
 Functions of riser are
 To feed metal to the solidifying casting, so that shrinkage cavities are got
rid off.
 It permits the escape of air and mould gases as the mould cavity is being
filled with the molten metal.
 It permits the directional solidification.
 It ensures that mould cavity is filled completely.

 Types of gates
 Parting line gates
 Top gates
 Bottom gates
 Side gates

 Types of Riser
 Top riser
 Side riser
 Open and blind riser

DESIGN OF RISER
 Shape of riser
 The risers are designed to solidify last so as to feed enough
metal to enough sections of the casting.
 The amount of heat and heat dissipation rate of riser depends on
its volume and surface area respectively.
 Hence for a given size, the riser should be designed with a high
volume to surface area ratio.
 To satisfy this condition, the riser is spherical or cylindrical
(most common) in shape.
 For riser design, Height of cyl. Riser = 1.5*dia. Of riser

DESIGN OF RISER
 Size of riser
 The freezing time of riser depends upon the amount of heat in a
casting and surface area of the casting.
 To determine the size of riser (casting) the following relations are
used
1. Chvorinov’s rule
2. Cain’s rule

CHVORINOV’S RULE
 Acco. to this rule, solidification time (freezing time) is a
function of volume of casting and its surface area.
𝒕 𝜶 (
𝑽
𝑺𝑨
)𝟐
𝒕 = 𝑪 (
𝑽
𝑺𝑨
)𝟐
 To achieve directional solidification, the riser must solidify
at last.
 Generally, (V/SA)riser > (V/SA)casting
(V/SA)riser = 1.1 to 1.15* (V/SA)casting
Where, t = solidification time in sec.
V= volume of casting in m3
SA = surface area of casting in m2
C = constant which depends upon the mould
material and metal to be cast

CAINE’S RULE
 Acco. to this rule
𝑿 =
𝒂
𝒀−𝒃
+ 𝐜
Where,
𝑿 =
(𝑺𝑨/𝑽)𝒄𝒂𝒔𝒕𝒊𝒏𝒈
(𝑺𝑨/𝑽)𝒓𝒊𝒔𝒆𝒓
…….(freezing ratio)
Y=
𝒗𝒐𝒍𝒖𝒎𝒆 𝒐𝒇 𝒓𝒊𝒔𝒆𝒓
𝒗𝒐𝒍𝒖𝒎𝒆 𝒐𝒇 𝒄𝒂𝒔𝒕𝒊𝒏𝒈
……….(volume ratio)
a = freezing characteristics constant
b= liquid to solidification contraction
c= relative freezing rate of riser and casting

SOLIDIFICATION OF METALS
 Solidification time (in sec.) acco. to Chvorinov’s rul
t = C (
𝑽
𝑺𝑨
)𝟐 …………for casting

INSPECTION OF CASTING
1. Destructive testing methods
2. Non-destructive testing methods
1. Visual inspection
2. Inspection for dimensional accuracy
3. Sound test
4. Impact test
5. pressure test

CASTING DEFECTS AND REMEDIES
Dec 2010,
May 2011,
May 2012,
Dec 2012,
May 2014

Sr.
No.
Defects Possible causes Effective remedies
1. Blow holes  Excess moisture in the
moulding sand
 Rust and moisture on chills,
chaplets used
 Cores are not sufficiently
baked
 Moulds are not adequately
vented
 Control moisture
 Use clean and rust free
chills, chaplets
 Bake the cores
properly
 Provide adequate
venting in moulds and
cores
2. Porosity  High temperature of
pouring
 Gas dissolved in metal
charge
 Slow solidification
 Regulate pouring
temperature
 Control metal
composition
 Modify gating and
risering
3. Shrinkage  Faulty gating and risering
and improper chilling
 Ensure proper
directional solidification
by modifying gating
system.

Sr.
No.
4. Hot tears
or hot
cracks
 Lack of collapsibility
 Lack of mould collapsibility
 Faulty design
 Hard ramming of mould
 Improve core
collapsibility
 Improve mould
collapsibility
 Modify the design
 Provide harder
ramming
5. Misrun and
cold shut
 Lack of fluidity in molten
metal
 Faulty design and gating
 Adjust proper pouring
temperature
 Modify the design and
gating system

Sr.
No.
7. Cuts and
washes
(Scabs)
 Low strength of mould and
core
 Faulty gating system
 Lack of binders in facing
and core sand
 Improve mould and
core strength
 Modify gating system
 Add more binders
8. Mismatch
(shifts)
 Worn out or bent clamping
pins
 Misalignment of two halves
of pattern
 Improper location and
support of core
 Faulty core boxes
 Repair or replace the
pins
 Replace dowel causing
misalignment
 Provide adequate core
support and locate it
properly
 Replace the core
boxes
9. Warpage  Continuous large flat surfaces
on casting , indicates poor
design
 Modify the casting design
to break the continuity of
the large flat surfaces

DIFFERENT CASTING PROCESSES
 Pressure Die-casting
Hot chamber
pressure die-casting
Cold chamber
pressure die-casting
May 2010, Dec 2011, May 2013
(Zn, mg, lead) (Al, Brass)

PRESSURE DIE-CASTING
 Advantages
 High production rates
 Economical for large scale production
 Close dimensional tolerances are possible.
 Good surface finish
 Thin sections upto 0.5 mm can be cast.
 Limitations
 Only suitable for smaller parts.
 Only non-ferrous alloys and metals can be commercially cast.
 High cost of equipments, dies.
 Due to entrapped air, die castings are porous which reduces mechanical
properties of the component.

CENTRIFUGAL CASTING
(a) True centrifugal casting May 2010, Dec 2010,
Dec 2011, Dec 2012,
May 2013

CENTRIFUGAL CASTING
(b) Semi-centrifugal casting

CENTRIFUGAL CASTING
(c) Centrifuging casting

INVESTMENT CASTING
 Steps
a)Die making
b)Wax patterns
and gating
system
c)Assembling
the wax
patterns
d)Precoating
e)Investing
f) Wax melting
g)Pouring
h)Cleaning and
Dec 2009, May
2010, May 2013,
May 2014, Dec
2014

INVESTMENT CASTING
 Advantages
 Better dimensional accuracy
 Complicated shapes and contours can be easily made.
 Extremely thin sections upto 0.75 mm can be cast.
 High surface finish
 Castings are sound and free from defects.
 Limitations
 Size of casting is limited.
 Moulds used are single purpose only.
 Cost of investment material is high.
 It is time consuming process.
 Applications
 Parts for aerospace industry, aircraft engines, frames, fuel systems, etc.
 Parts for food and beverage machinery, computer and data processing equipments,
machine tools and accessories.
 Nozzles, buckets, blades, etc. for gas turbines.
 Costume jewellery

CONTINUOUS CASTING
Dec 2009, May 2010

CONTINUOUS CASTING
 Advantages
 The process is cheaper than rolling from ingots.
 There is no need of rough forming and breakdown rolling
operation.
 Casting surfaces obtained are better than the static ingots.
 Grain size and structure of the casting can be regulated by
controlling cooling rates.
 Casting is more dense and uniform than individual castings.
 Castings have improved quality.
 Applications
 This process can produce any shape of uniform cross-section
such as rectangular, square, hexagonal, gear toothed, etc. either
solid or hollow.
 Production of blooms, billets, slabs and sheets
 Materials like brass, zinc, copper and its alloys, aluminium and
its alloys, alloy steel may be cast.

CLEANING OF CASTING
 Removal of dry sand cores
 Removal of gates and risers
 Removal of unwanted metal projections and fins
 Removal of adhered sand and oxide scale
 Wire brushing
 Tumbling
 Sand blasting
 Shot blasting
 Hydro blasting
 pickling
May 2013

METALS FOR CASTING
1. Ferrous casting alloys
 Cast iron
 Steel
2. Non-ferrous casting alloys
 Aluminium alloys
 Magnesium alloys
 Copper alloys
 Tin based alloys
 Zinc alloys
 Nickel alloys
 Titanium alloys

10 Types of Casting Patterns Explained

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