Introduction to material science

Question 1

What are the three scales a material may be considered in?

Answer 1

Subatomic
Microscopic
Macroscopic

Question 2

What are the six properties of a material?

Answer 2

Mechanical
Electrical
Magnetic
Thermal
Optical
Deteriorative

Question 3

What are the three general material selection criteria?

Answer 3

In-service conditions, deterioration and economics

Question 4

What is a metal?

Answer 4

Materials in this group are composed of one or more metallic element (e.g iron, aluminum, copper, titanium) and often smaller amounts of non-metallic elements (e.g. carbon, nitrogen, oxygen etc.).

Question 5

What are mechanical properties of a metal

Answer 5

Metals are relatively stiff and strong, yet are ductile (i.e., capable of large amounts of deformation without fracture), and are resistant to fracture

Question 6

What is a ceramic?

Answer 6

Ceramic materials are compounds composed of metallic and non-metallic elements which are most frequently oxides, nitrides or carbides.

Question 7

What are mechanical properties of a ceramic?

Answer 7

Ceramic materials are relatively stiff and strong, with stiffnesses and strengths comparable to those of the metals. In addition, ceramics are typically very hard. On the other hand, they are extremely brittle (lack ductility), and are highly susceptible to fracture.

Question 8

What is a polymer?

Answer 8

A polymer is a long molecular chain mainly made up of carbon, hydrogen and other non-metallic elements (i.e. O, N, Si).

Question 9

What are the mechanical properties of a polymer?

Answer 9

These materials typically have low densities, whereas their mechanical characteristics are generally dissimilar to the metallic and ceramic materials. They are not as stiff nor as strong as these other material types. However, on the basis of their low densities, many times their stiffnesses and strengths on a per mass basis are comparable to the metals and ceramics. In addition, many of the polymers are extremely ductile and pliable (i.e., plastic), which means they are easily formed into complex shapes.

Question 10

What is a composite?

Answer 10

A composite is composed of two (or more) individual materials, which come from metals, ceramics, and polymers.