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Credit Hour SystemsPRODUCTION TECHNOLOGY –MDP024

Freshman Students – Group (3)

Report On:٧(4)

Casting السباكة

Student Name:

ID:

Submitted to:Dr. Mohamed Ahmed Awad

Laboratory Report (4) : Casting

MDP 024 – Prepared by Dr. Mohamed Ahmed Awad - 1 -

Objective

The objective of this report is to study the casting

process to understand its basic principles,

classifications, procedure and its equipment.

By the end of this report, the student must be able to

do the following:

Define the casting process.

Identify the elements of molds, the usage of each

one.

Identify the different types of products produced

by casting process.

Identify the foundry tools

Give examples of real cast product for each type.

Classify the different types of molds and state the

constraints which control the usage of each of

them.

Describe the technological steps required for

casting process

Implement the previous steps for sand casting

process.



Casting

Casting is the process of pouring molten metal into a

mould containing a cavity, which represents the

required product shape. It is one of the most

commonly used processes for making parts is

casting. The general term Casting covers sand, shell

mold, investment, plaster mold, centrifugal,

permanent, die, continuous and powder metallurgy

casting.

Types of Casting

Molds may be made of sand, metal, plaster, ceramics

or other refractive substances. The choice of casting

types depends on several factors such as complexity,

surface finish and cost.



Basic process

There are six steps in this process:

1. Place a pattern in sand to create a mold.

2. Incorporate the pattern and sand in a gating

system.

3. Remove the pattern.

4. Fill the mold cavity with molten metal.

5. Allow the metal to cool.

6. Break away the sand mold and remove the

casting.

Green sand

These expendable molds are made of wet sands that

are used to make the mold's shape. The name comes

from the fact that wet sands are used in the molding



process. Green sand is not green in color, but

"green" in the sense that it is used in a wet state.

Molding sands

Molding sands, also known as foundry sands, are

defined by eight characteristics: refractoriness,

chemical inertness, permeability, surface finish,

cohesiveness, flowability, collapsibility, and

availability/cost.

Refractoriness — This refers to the sand's ability to

withstand the temperature of the liquid metal being

cast without breaking down.

Chemical inertness — The sand must not react

with the metal being cast. This is especially

important with highly reactive metals, such as

magnesium and titanium.

Permeability — This refers to the sand's ability to

exhaust gases. This is important because during the

pouring process many gases are produced.

Surface finish — The size and shape of the sand

particles defines the best surface finish achievable,



with finer particles producing a better finish.

However, as the particles become finer (and surface

finish improves) the permeability becomes worse.

Cohesiveness (or bond) — This is the ability of the

sand to retain a given shape after the pattern is

removed.

Flowability – The ability for the sand to flow into

intricate details and tight corners without special

processes or equipment.

Availability/cost — The availability and cost of the

sand is very important because for every ton of metal

poured, three to six tons of sand is required.

Types of base sands

Base sand is the type used to make the mold or core

without any binder. Because it does not have a

binder it will not bond together and is not usable in

this state.



Experimental sand mould preparation







Tooling

The main tooling for sand casting is the pattern that

is used to create the mold cavity. The pattern is a full

size model of the part that makes an impression in

the sand mold.

Several different materials can be used to fabricate a

pattern, including wood, plastic, and metal. Wood is

very common because it is easy to shape and is

inexpensive, however it can warp and deform easily.

A pattern for a part can be made many different

ways, which are classified into four types; however

the most common used are :

Solid pattern - A solid pattern is a model of the

part as a single piece. It is the easiest to fabricate,

but can cause some difficulties in making the

mold.



Solid pattern

Split pattern - A split pattern models the part as two

separate pieces that meet along the parting line of

the mold. Using two separate pieces allows the mold

cavities in the cope and drag to be made separately

and the parting line is already determined. Split

patterns are typically used for parts that are

geometrically complex and are produced in moderate

quantities.

Split pattern



Complete Mold and its elements during pouring



Hand tools used in Sand Casting



Example

The Sand Casting process includes packing sand

around a pattern to form a mold. A pattern is the

same form, allowing for shrinkage, that the final

casting will be. The mold is in 2 parts so the pattern

can then be removed and the metal poured in to the

resulting cavity. We use a synthetic sand that is

mixed with a binder so it forms a smooth surface

when packed. The castings are finished by removing

the parting line and gating areas. The castings are

then sand or glass bead blasted or tumbled in

ceramic chips to enhance the finish.



Exercise

Casting Fundamentals

What is casing?

Elements of mold

Identify each of the following mold part?

Flask Cope Drag

Core Draft Parting Line

Sand Gating Sys Cavity

LaboratoryReport(4):Casting


Identify the foundry tools shown below then write their

Identification No. in the table

1 2 3

4 5 6

7 8 9

10 11 12



Name No Function

Flask It is used as container for sand

Slick and Oval Used for repairing and finishing the mold

surfaces and their edges after withdrawal of

the pattern

Bench Rammer Used in striking the sand in the molding box

Gate Cutter Used to cut runners and feeding gates

Sprue Pin Used to join mold cavity while cope sand in

being rammed

Trowel Used for smoothing the surface of molds and

cut in gate and repair the mold surface

Vent Wine Used to pierce series of small holes in the

molding sand in the cope portion

Molding Board It is used as mold base

Sponge Used in smoothing and finishing the corners

and edges of mold



Bellows Used to blow away the loose or unwanted

sand from the surface of mold cavities

Riddle Used for cleaning the sand for removing

foreign material from sand

Strike Off Bar Used to strike or remove the excess sand

from the top molding box



Describe in details the steps required to cast the followingproduct?

Drawing Drawing

Molding Preparation1. Drawing Description

2. Drawing Description






6.

Drawing Description



Study the Solidification of MetalsSolidification is the transformation of molten metal back into

solid state. Solidification differs depending on whether the metal

is a pure element or an alloy. Solidification process is shown in

Fig.

Solidification process



Describe the reasons for the shown Casting Defects

Mis run

Cold Shot

Shrinkage Cavity

Sand Blow

Mold Shift

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ﺔﻛﺎﺒﺴﻟا - mohamedawad.com · Laboratory Report (4) : Casting MDP 024 – Prepared by Dr. Mohamed Ahmed Awad - 10 - Solid pattern Split pattern - A split pattern models