NATURE OF MATERIALS - Materials for Civil and Construction Engineers - page 84

2.12 Calculate the volume of the unit cell of iron in cubic meters, given
that iron has a body-center cubic crystal structure and an atomic
radius of 0.124 nm.
2.13 If aluminum has an FCC crystal structure and an atomic radius of
0.143 nm, calculate the volume of its unit cell in cubic meters.
2.14 Using the information available in Table 2.3, calculate the volume of
the unit cell of copper in cubic meters.
2.15 Calculate the density of iron, given that it has a BCC crystal structure,
an atomic radius of 0.124 nm, and an atomic mass of 55.9 g/mole.
2.16 Calculate the density of aluminum, given that it has an FCC crystal
structure, an atomic radius of 0.143 nm, and an atomic mass of
26.98 g/mole.
2.17 Calculate the radius of the copper atom, given that copper has an
FCC crystal structure, a density of 8.89 g/cm 3 ,

and an atomic mass of

63.55 g/mole.
2.18 What are the classes of defects in crystal structures?
2.19 Why do grains form in crystal structures?
2.20 Explain the slipping of atoms and the effect on material
deformation.
2.21 Sketch a phase diagram for two soluble components.
2.22 What is the eutectic composition and why is it important?
2.23 Considering an alloy of the two soluble components A and B
described by a phase diagram similar to that shown in Figure 2.14,
determine the masses of the alloy that are in the liquid and solid
phases at a given temperature if the total mass of the alloy is 100
grams, component B represents 65% of the alloy, 30% of the liquid
is component B, and 80% of solid is component B.
2.24 Considering an alloy of the two soluble components A and B
described by a phase diagram similar to that shown in Figure 2.14,
determine the masses of the alloy that are in the liquid and solid
phases at a given temperature if the total mass of the alloy is 100
grams, component B represents 45% of the alloy, 17% of the liquid
is component B, and 65% of solid is component B.
2.25 Figure P2.25 shows a portion of the -NaCl phase diagram.
a. Using the diagram, briefly explain how spreading salt on ice causes
the ice to melt. Show numerical examples in your discussion.
b. At a salt composition of 10%, what is the temperature at which
ice will start melting?
c. What is the eutectic temperature of the ice and salt combination?
2.26 What are the five classes of ceramic materials?
2.27 What are the four types of organic solids used in engineering appli-
cations? Define each one and give examples.

H 2 O