Chapter 1

Question 1

What is materials science?

Answer 1

The study of the relationships between structures and properties of materials as well as research into the development of new materials.

Question 2

What is materials engineering?

Answer 2

The creation of products from existing materials and the development of materials processing techniques.

Question 3

What were the three major material ages?

Answer 3

Stone, bronze, and iron.

Question 4

How are the properties of materials determined?

Answer 4

By their structures

Question 5

What are the 4 levels of structure?

Answer 5

1. Atomic structure
2. Atomic arrangement
3. Microstructure
4. Macrostructure

Question 6

What is a property?

Answer 6

A material’s response to a stimulus and is independent of size and shape.

Question 7

What are the relationships between processing, structure, and properties?

Answer 7

Structure is dependent on processing. Properties are dependent on structure.

Question 8

What are the three classifications of materials?

Answer 8

• Metals
• Plastics/polymers
• Ceramics

Question 9

What are the properties of metals?

Answer 9

• Strong, ductile
• High thermal and electrical conductivity due to non-localized electrons
• Opaque, reflective

Question 10

What are the properties of polymers/plastics?

Answer 10

• Compounds of non-metallic elements
• Soft, ductile, low strength, low density
• Low thermal and electrical conductivity
• Opaque, translucent, or transparent

Question 11

What are the properties of ceramics?

Answer 11

• Compounds of metallic and non-metallic elements
• Hard, brittle
• Low thermal and electrical conductivities
• Opaque, translucent, or transparent

Question 12

List the materials in order of conductivity: ceramics, metals, polymers, semiconductors.

Answer 12

1. Metals
2. Semiconductors
3. Ceramics
4. Polymers

Question 13

List the order of procedure in materials selection.

Answer 13

1. Application
2. Properties
3. Materials
4. Processes

Question 14

What are the six material property types?

Answer 14

• Mechanical
• Electrical
• Thermal
• Magnetic
• Optical
• Deteriorative

Question 15

What do mechanical properties relate to?

Answer 15

Deformations

Question 16

How does carbon content affect the hardness of a common steel?

Answer 16

Increasing carbon content increases the hardness of steel.

Question 17

What do electrical properties relate to?

Answer 17

Electrical resistivity

Question 18

What are three ways to increase resistivity?

Answer 18

• Increasing temperature (atoms excite and make it harder for electrons to travel)
• Increase impurity (impurities act like barriers so electrons get slowed moving around)
• Deform (disrupts the structure changing the path electrons take)

Question 19

What do thermal properties relate to?

Answer 19

Thermal conductivity

Question 20

What is one way to decrease thermal conductivity?

Answer 20

Increase impurity

Question 21

Why are highly porous materials poor conductors of heat?

Answer 21

Porous materials have significant void spaces or gaps that hold air, which is a poor conductor of heat.

Question 22

What do magnetic properties relate to?

Answer 22

Magnetic storage (the ability to store magnetic charges) and magnetic permeability (the ability to magnetize under an applied magnetic field).

Question 23

What do optical properties relate to?

Answer 23

Light transmittance

Question 24

What is the difference between single-crystal and polycrystalline structures?

Answer 24

Single-crystal structures are composed of atoms aligned in one direction.
Polycrystalline structures are composed of grains, where atoms in each grain are aligned in one direction.

Question 25

What do deteriorative properties relate to?

Answer 25

Chemical reactivity