Metal Casting: Fundamentals and Applications

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Questions and Answers

What is the primary function of a mold in the metal casting process?

To resist the high temperature of the molten metal (correct)

To shape the metal into its desired form

To cool the molten metal

To machine the metal object

What is the result of pouring molten metal into a mold and allowing it to solidify?

A welded product

A forged product

A machined product

A casting (correct)

Which of the following is an advantage of the metal casting process?

Allows for the creation of intricate shapes (correct)

Is limited to small-sized products

Requires expensive tools and machinery

Can only be used for ferrous materials

What is the primary reason why metal casting is used in manufacturing?

It can create intricate shapes and minimize other operations Signup and view all the answers

What is the benefit of using metal casting in manufacturing?

It allows for large savings in weight Signup and view all the answers

What is a limitation of the metal casting process?

The size and weight of the product are limitations Signup and view all the answers

What is the purpose of using sand as a mold material in metal casting?

It resists the high temperature of the molten metal Signup and view all the answers

What is a characteristic of metal casting that allows for the creation of intricate parts?

Molten material can flow into very small sections Signup and view all the answers

Which of the following woods is available in the Himalayas and is known for its strong and durable wood?

Deodar Signup and view all the answers

Which of the following characteristics is NOT associated with Mahogany wood?

It is soft and cheap Signup and view all the answers

What is the main advantage of using wooden patterns in casting?

They are very cheap and easily available Signup and view all the answers

Which of the following metals is known for its good resistance to sand abrasion and corrosion?

Cast Iron Signup and view all the answers

What is the main disadvantage of using metallic patterns in casting?

They are heavy and expensive Signup and view all the answers

Which of the following woods is known for its fragrance and is available in the Himalayas at a height of 1500 to 3000 meters?

Deodar Signup and view all the answers

What is the main advantage of using Brass and Bronze patterns in casting?

They have better surface finish than cast iron Signup and view all the answers

Which of the following is a disadvantage of using Cast Iron patterns in casting?

They are heavy and brittle Signup and view all the answers

What is a limitation of the sand casting process?

Dimensional accuracy and surface finish Signup and view all the answers

What is the purpose of facing sand in the sand casting process?

To give a better surface finish to the castings Signup and view all the answers

What is the name of the upper molding flask in the sand casting process?

Cope Signup and view all the answers

What is the purpose of vent holes in the sand casting process?

To permit the escape of gases generated during pouring and solidification Signup and view all the answers

What is the replica of the final object to be made in the sand casting process?

Pattern Signup and view all the answers

What is the purpose of the gating system in the sand casting process?

To create a pathway for the molten metal to flow into the mold cavity Signup and view all the answers

What is the role of the drag in the sand casting process?

To form the lower part of the mold Signup and view all the answers

What is the purpose of molding sand in the sand casting process?

To bind strongly without losing its permeability to air or gases Signup and view all the answers

What is the primary function of a core in a mold?

To create openings and various shaped cavities in the castings Signup and view all the answers

What is the purpose of a pouring basin in a mold?

To receive the molten metal and direct it into the mold Signup and view all the answers

What is the role of a sprue in a mold?

To carry the molten metal from the pouring basin to the gate Signup and view all the answers

What is the purpose of a gate in a mold?

To create a channel for the molten metal to enter the mold cavity Signup and view all the answers

What is the role of chaplets in a mold?

To support the cores inside the mold cavity Signup and view all the answers

What is the primary function of a pattern in casting?

To create a cavity in the molding sand Signup and view all the answers

Which of the following is a common material used for making patterns?

Wood Signup and view all the answers

What is the advantage of using wooden patterns in casting?

It is cheap and can produce highly smooth surfaces Signup and view all the answers

What is the primary advantage of aluminum alloy patterns?

Good surface finish and low melting point Signup and view all the answers

Which of the following is a disadvantage of White Metal patterns?

Softness and requirement of proper care for storage and transportation Signup and view all the answers

What is the primary advantage of plastic patterns?

Lighter, stronger, moisture and wear resistant, and non-sticky to molding sand Signup and view all the answers

What is the primary advantage of plaster patterns?

High compressive strength and high expansion setting type Signup and view all the answers

What is the primary advantage of wax patterns?

Ability to impart a high degree of surface finish and dimensional accuracy Signup and view all the answers

What is a disadvantage of aluminum alloy patterns?

They can be damaged by sharp edges Signup and view all the answers

What is a common type of plastic used for making patterns?

Phenolic resin Signup and view all the answers

What is a common method of making wax patterns?

Injecting liquid wax into a split die Signup and view all the answers

Study Notes

Metal Casting

Metal casting is a vital industry that plays a key role in all major sectors of the economy.
It is one of the oldest materials shaping methods known, where molten metal is poured into a mold to create a desired shape.
The mold is made of a heat-resistant material, such as sand, and is broken or taken apart to reveal the solidified metal object, known as a casting.

Advantages of Metal Casting

Intricate shapes can be made with high accuracy.
Practically any material can be cast, including ferrous and non-ferrous metals.
Weight can be saved by placing metal exactly where it is needed.
Simple and inexpensive tools are required for casting molds.
Certain parts can only be made using this process.
There is no limitation to the size and weight of the product.

Limitations of Metal Casting

Dimensional accuracy and surface finish can be limited by the sand casting process.
New casting processes, such as die casting, investment casting, and vacuum-sealed molding, have been developed to improve accuracy and surface finish.

Components Used for Making a Mould Cavity

Molding box: A suitable size of molding box is selected for creating a suitable wall thickness.
Pattern: A replica of the final object to be made, used to create the mold cavity.
Parting line: The dividing line between the two molding flasks that make up the mold.
Molding sand: A mixture of silica sand, clay, and moisture, used to bind the mold.
Facing sand: A small amount of carbonaceous material used to give a better surface finish to the castings.
Core: A separate part of the mold, used to create openings and shaped cavities in the castings.
Pouring basin: A small funnel-shaped cavity at the top of the mold, used to pour the molten metal.
Sprue: A passage through which the molten metal reaches the mold cavity.
Runner: A channel that carries the molten metal from the sprue to the gate.
Gate: A channel through which the molten metal enters the mold cavity.
Chaplets: Used to support the cores inside the mold cavity.
Riser: A column of molten metal placed in the mold to feed the castings as they shrink and solidify.
Vent: A small opening in the mold to facilitate the escape of air and gases.

Pattern Making

A pattern is a model or replica of the object to be cast.
It is used to create a mold cavity in the molding sand.
Pattern materials include wood, metal, plastic, plaster, wax, and mercury.
The choice of pattern material depends on the quality of the casting required, the number of castings to be produced, and the cost.

Common Pattern Materials

Wood: A popular and commonly used material for pattern making, due to its low cost, ease of fabrication, and light weight.
Metal: Preferred when the number of castings required is large, due to its durability, strength, and resistance to corrosion and wear.
Plastic: A newer material being used for pattern making, due to its light weight, strength, and durability.
Plaster: A material used for producing highly intricate castings, due to its high compressive strength and high expansion setting type.
Wax: Used for investment casting, due to its ability to impart a high degree of surface finish and dimensional accuracy to castings.

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Description

This quiz covers the basics of metal casting, its importance in various industries, and its applications in daily life.