Callister - An introduction - 8th edition

6 • Chapter 1 / Introduction
Figure 1.3
Bar chart of roomtemperature
density
values for various
metals, ceramics,
polymers, and
composite materials.
Density (g/cm 3 ) (logarithmic scale)
40
20
10
8
6
4
2
1.0
0.8
0.6
0.4
Metals
Platinum
Silver
Copper
Iron/Steel
Titanium
Aluminum
Magnesium
Ceramics
ZrO 2Al2
O 3
SiC,Si 3 N 4
Glass
Concrete
Polymers
PTFE
PVC
PS
PE
Rubber
Composites
GFRC
CFRC
Woods
0.2
0.1
regard to mechanical characteristics, these materials are relatively stiff (Figure 1.4)
and strong (Figure 1.5), yet are ductile (i.e., capable of large amounts of deformation
without fracture), and are resistant to fracture (Figure 1.6), which accounts for their
widespread use in structural applications. Metallic materials have large numbers of
nonlocalized electrons; that is, these electrons are not bound to particular atoms. Many
properties of metals are directly attributable to these electrons. For example, metals
are extremely good conductors of electricity (Figure 1.7) and heat, and are not transparent
to visible light; a polished metal surface has a lustrous appearance. In addition,
some of the metals (i.e., Fe, Co, and Ni) have desirable magnetic properties.
Figure 1.8 shows several common and familiar objects that are made of metallic
materials. Furthermore, the types and applications of metals and their alloys are
discussed in Chapter 11.
Ceramics
Ceramics are compounds between metallic and nonmetallic elements; they are most
frequently oxides, nitrides, and carbides. For example, common ceramic materials
Figure 1.4
Bar chart of roomtemperature
stiffness
(i.e., elastic modulus)
values for various
metals, ceramics,
polymers, and
composite materials.
Stiffness [Elastic (or Young’s) Modulus (in units of
gigapascals)] (logarithmic scale)
1000
100
10
1.0
0.1
0.01
Metals
Tungsten
Iron/Steel
Titanium
Aluminum
Magnesium
Ceramics
SiC
AI 2 O 3
Si 3 N 4
ZrO 2
Glass
Concrete
Polymers
PVC
PS, Nylon
PTFE
PE
Rubbers
Composites
CFRC
GFRC
Woods
0.001