Properties of Materials for Engineering

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Questions and Answers

What is the primary characteristic of metals that accounts for their widespread use in structural applications?

Low density and high transparency

High ductility and resistance to fracture (correct)

Magnetic properties and low thermal conductivity

Good electrical conductivity

Which of the following is NOT a characteristic of metals?

High density

High transparency to visible light (correct)

Good mechanical properties

Good electrical conductivity

What is the term for a combination of a metal with at least one other metal or non-metal?

Polymer

Composite

Ceramic

Alloy (correct)

Which of the following metals is NOT ferrous?

Copper Signup and view all the answers

What is the purpose of alloying and mechanical and heat treatment in metals?

To make them stronger and more resistant to deformation Signup and view all the answers

Which of the following is a characteristic of ferrous metals?

Desirable magnetic properties Signup and view all the answers

What is the primary difference between ferrous and non-ferrous metals?

Their composition Signup and view all the answers

What is the term for materials that are composed of one or more metallic elements and often non-metallic elements in relatively small amounts?

Metals Signup and view all the answers

What is the primary reason for the high hardness and brittleness of white cast iron?

The formation of a network of interlocking crystals of cementite Signup and view all the answers

Which type of cast iron has a higher level of vibration damping compared to steel?

Grey cast iron Signup and view all the answers

What is the primary component of grey cast iron that forms during the cooling process?

Graphite Signup and view all the answers

Which of the following is a characteristic of grey cast iron?

Easier to machine than other cast irons Signup and view all the answers

What is the primary difference between white cast iron and grey cast iron?

The presence of graphite Signup and view all the answers

Which type of cast iron is more resistant to rust?

Grey cast iron Signup and view all the answers

What is the primary reason for the light appearance of white cast iron?

The absence of graphite Signup and view all the answers

What elements are added to cast iron to produce grey cast iron?

C, Si, Mn, S, P Signup and view all the answers

Which of the following materials is not typically used in engineering applications?

Fibers Signup and view all the answers

What is the primary reason for learning about materials in engineering?

To make informed decisions in engineering applications Signup and view all the answers

Which of the following learning outcomes is not directly related to material properties?

Design a manufacturing process for a new material Signup and view all the answers

What is the primary purpose of testing engineering materials?

To determine the material's properties under external loads Signup and view all the answers

Which of the following materials is a type of ceramic?

Glass Signup and view all the answers

What is the primary focus of Learning Outcome 4?

Testing samples of metals to determine their properties Signup and view all the answers

What is the primary reason for the brittleness of white cast irons?

Presence of large particles of carbon Signup and view all the answers

What is the main difference between white cast iron and malleable cast iron?

Heat treatment process Signup and view all the answers

What is the result of the formation of carbide during solidification in Malleable Iron?

Conventional shrinkage behaviour Signup and view all the answers

What is the primary reason for the use of white cast iron in mining equipment and cement mill rolls?

Abrasion resistance Signup and view all the answers

What is the characteristic of graphite in Malleable Iron that gives it ductility and strength?

Compact or sphere-like form Signup and view all the answers

What determines the type of Malleable Iron depending on the annealing treatment?

Silicon content Signup and view all the answers

What is the temperature range for the first stage of heat treatment for Pearlite malleable iron?

940˚C in a controlled atmosphere Signup and view all the answers

What is the primary advantage of ductile cast iron over grey cast iron?

Higher strength Signup and view all the answers

What is the result of adding magnesium to the molten iron in the production of ductile cast iron?

Formation of nodule shaped graphite Signup and view all the answers

What is the characteristic of malleable cast iron that makes it suitable for heavy-duty applications?

Good shock resistance properties Signup and view all the answers

What is the primary application of ductile cast iron?

Automotive industry Signup and view all the answers

What is the advantage of ductile cast iron in terms of manufacturing process?

Low cost Signup and view all the answers

What is the characteristic of ductile cast iron that affects its casting process?

Low shrinkage Signup and view all the answers

What is the similarity between malleable cast iron and ductile cast iron?

Both have good machinability Signup and view all the answers

Study Notes

Types of Materials

Learning about materials is a key decision for most engineering applications.
Different classes of materials:
- Metals
- Alloys
- Ceramics
- Polymers
- Rubber
- Plastics
- Timber
- Cement
- Sand
- Silicon
- Glass
- Rock aggregates
- Clay

Types of Materials (Continued)

New engineering materials and adhesives
General classification for materials used in engineering:
- Metals
- Non-Metals
  - Polymers
  - Semi-conductors
  - Ceramics
  - Composites

Metals

Composed of one or more metallic elements (e.g., iron, aluminum, copper, titanium, gold, nickel)
Often also non-metallic elements (e.g., carbon, nitrogen, oxygen) in relatively small amounts
Relatively dense
Show good mechanical properties:
- Relatively stiff
- Strong
- Ductile (i.e., capable of large amounts of deformation without fracture)
- Resistant to fracture
Extremely good conductors of electricity and heat
Not transparent to visible light
Some metals have desirable magnetic properties
When pure, are soft and easily deformed, but can be made strong by alloying and by mechanical and heat treatment

Classification of Metals

Ferrous metals and alloys
Non-Ferrous metals and alloys
- Alloys (Non-Fe + other elements)

Ferrous Metals and Alloys

Alloys (Fe + other elements)
Cast iron
- Grey cast iron
  - Characteristics:
    - Better thermal conductor
    - Higher level of vibration damping
    - Easier to machine
    - Not as ductile
    - Highly resistant to rust
  - Applications:
    - Engine blocks
    - Gearbox cases
    - Cylinder heads
- White cast iron
  - Characteristics:
    - Carbon present only as carbide
    - High hardness and brittleness
    - Low silicon content
    - Low melting point
  - Application:
    - Brake rotors
    - Gears
    - Bearings
    - Dies
    - Moulds
    - Mining equipment
    - Cement mill rolls
- Malleable cast iron
  - Characteristics:
    - Excellent machinability
    - Significant ductility
    - Good shock resistance properties
  - Applications:
    - Connecting rods and universal joint yokes
    - Transmission gears
    - Differential cases
    - Compressor crankshafts and hubs
    - Flanges
    - Pipe fittings
    - Valve parts
- Nodular (ductile) cast iron
  - Characteristics:
    - Strength higher than grey cast iron
    - Ductility up to 6% as cast or 20% annealed
    - Low cost
    - Simple manufacturing process
    - Machineability better than steel
    - Low shrinkage during casting
  - Application:
    - Automotive industry

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Description

This quiz covers the importance of learning about materials in engineering, different classes of materials, their properties, and testing. It also touches on material selection criteria for simple engineering applications.