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LEARNING OBJECTIVES
PREFACE
Accreditation standards, as mandated by many engineering accreditationorganizations, now include outcome assessment components. Often one of thesecomponents includes the delineation of detailed educational objectives, and, inaddition, some means of evaluating whether or not these objectives have beenachieved by the students. One way of addressing this issue is for instructors indepartments of engineering to incorporate learning objectives in their course offerings.There appear on the first page of each of the textbook chapters several learningobjectives, general in nature, that are relevant to that chapter's content. Furthermore,we have included here, a detailed list of objectives for each of the 22 chapters. Webelieve that, in addition, to providing outcome assessment criteria, these objectiveswill also help the instructor to organize the course subject material and also givedirection to the classroom presentations; in addition, objectives allow the instructor toascertain whether or not the intended course goals have been achieved. Whendistributed to and used by the students, their studying becomes more focused andeffective, and preparation for examinations is facilitated.
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CHAPTER 1
INTRODUCTION
LEARNING OBJECTIVES
1. List six different property classifications of materials that determine their
applicability.
2. Define what is meant by a structural element of a material, and then cite two
structural elements.
3. (a) Cite the four components that are involved in the design, production, and
utilization of materials.
(b) Now, briefly describe the interrelationships between these components.
4. Cite three criteria that are important in the materials selection process.
5. (a) List the three primary classifications of solid materials, and then cite the
distinctive chemical feature of each.
(b) In addition, note the other three types of materials, and, for each, its
distinctive feature(s).
6. (a) Briefly define “smart material/system.”
(b) Briefly explain the concept of “nanotechnology” as it applies to materials.
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CHAPTER 2
ATOMIC STRUCTURE AND INTERATOMIC BONDING
LEARNING OBJECTIVES
1. Name the two atomic models cited, and note the differences between them.
2. Describe the important quantum-mechanical principle that relates to electron
energies.
3. (a) Name the four electron quantum numbers.
(b) For a specific electron, note what each of its quantum numbers
determines.
4. Write a definition of the Pauli exclusion principle.
5. Cite the general characteristics of the elements that are arrayed in each
column of the periodic table.
6. Write the equation that relates energy and force.
7. (a) Schematically plot attractive, repulsive, and net energies versus
interatomic separation for two atoms or ions.
(b) Now note on this plot the equilibrium separation and the bonding energy.
8. (a) Briefly describe ionic, covalent, metallic, hydrogen, and van der Waal's
bonds.
(b) Now note what materials exhibit each of these bonding types.
9. Given the chemical formula for a material, be able to cite what bonding
type(s) is (are) possible.
10. Given the electronegativities of two elements, compute the percent ionic
character of the bond that forms between them.
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CHAPTER 3
THE STRUCTURE OF CRYSTALLINE SOLIDS
LEARNING OBJECTIVES
1. Give a definition of a crystalline solid.
2. Describe the difference between crystalline and noncrystalline materials.
3. Give a brief definition of a unit cell.
4. Schematically diagram face-centered cubic, body-centered cubic, and
hexagonal close-packed unit cells.
5. Given the atomic radius of an atom that forms into a face-centered cubic
crystal structure as well as the metal's atomic weight, compute its density.
6. Given the atomic radius of an atom that forms into a body-centered cubic
crystal structure as well as the metal's atomic weight, compute its density.
7. (a) Explain what is meant by coordination number and atomic packing
factor.
(b) Cite the atomic packing factors and coordination numbers for body-
centered cubic, face-centered cubic, and hexagonal close-packed crystal
structures.
8. Briefly define polymorphism (or allotropy).
9. Distinguish between crystal system and crystal structure.
10. Recognize and also give the lattice parameter relationships for all seven
crystal systems--i.e., cubic, hexagonal, tetragonal, rhombohedral,
orthorhombic, monoclinic, and triclinic.
11. Given a unit cell and three point coordinates, locate the point represented
by these indices within the unit cell.
12. Given the location of a point within a unit cell, specify its point coordinates
13. Given a unit cell and three direction indices, draw the direction represented
by these indices referenced to this unit cell.
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14. Given a direction that has been drawn referenced to a unit cell, specify its
direction indices.
15. Given a unit cell and the Miller indices for a plane, draw the plane
represented by these indices referenced to this unit cell.
16. Given a plane that has been drawn referenced to a unit cell, specify its
Miller indices.
17. For hexagonal crystals, be able to convert both directional and planar
indices from the three-axes scheme to the four-axes (Miller Bravais)
scheme.
18. Given the unit cell for some crystal structure, be able to draw the atomic
packing arrangement for a specific crystallographic plane.
19. Define both linear and planar atomic densities.
20. For a given crystal structure, be able to determine the linear density for a
specified crystallographic direction.
21. For a given crystal structure, be able to determine the planar density for a
specified crystallographic plane.
22. (a) Draw the packing of a close-packed plane of spheres (atoms).
(b) Describe how both hexagonal close-packed and face-centered cubic
crystal structures may be generated by the stacking of close-packed
planes.
(c) Cite which planes in both hexagonal close-packed and face-centered
cubic structures are close-packed.
23. Briefly cite the difference between single crystals and polycrystalline
materials.
24. Define grain boundary.
25. Give definitions for isotropy and anisotropy.
26W. Briefly describe the phenomenon of diffraction.
27W. Given the angle at which an x-ray diffraction peak occurs, as well as the
x-ray wavelength and order of reflection, compute the interplanar spacing
for the crystallographic planes that are responsible for the diffraction peak.
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28W. For crystals having cubic symmetry, given the lattice parameter (i.e., unit
cell edge length), compute the interplanar spacing for a set of
crystallographic planes of specified Miller indices.
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CHAPTER 4
IMPERFECTIONS IN SOLIDS
LEARNING OBJECTIVES
1. Describe both vacancy and self-interstitial crystalline defects.
2. Given the density and atomic weight for some material, as well as
Avogardo's number, compute the number of atomic sites per cubic meter
3. For some material, given the number of atomic sites per cubic meter, the
energy required for vacancy formation, and, in addition, the value for the
gas constant, compute the number of vacancies at some specified
temperature.
4. Define what is meant by the term "alloy".
5. State the two types of solid solutions, and provide a brief written definition
and/or schematic diagram of each.
6. State the criteria for the formation of each of substitutional and interstitial
solid solutions.
7. Given the atomic radii of host and impurity atoms, as well as their crystal
structures, electronegativities, and valences, determine if solid solutions
that form are (a) substitutional with appreciable solubility, (b)
substitutional with limited solubility, or (c) interstitial.
8. Given the masses and atomic weights of two or more elements in a metal
alloy, compute the weight percent and atomic percent of each element.
9. (a) Given the composition (in weight percent) and atomic weights for two
elements in an alloy, determine the composition in atom percent.
(b) Make a composition conversion from atom percent to weight percent.
10. Given the atomic weights and densities for two elements in an alloy:
(a) Determine the average density when the composition is specified in
weight percent.
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(b) Determine the average density when the composition is specified in atom
percent.
11. Given the atomic weight for each of two elements in an alloy:
(a) Determine the average atomic weight when the composition is specified
in weight percent.
(b) Determine the average atomic weight when the composition is specified
in atom percent.
12. For each of edge, screw, and mixed dislocations:
(a) describe and make a drawing of the dislocation;
(b) note the location of the dislocation line; and
(c) indicate the direction along which the dislocation line extends.
13. (a) Describe the atomic structure within the vicinity of a grain boundary.
(b) Make a distinction between high- and small-angle grain boundaries.
(c) Explain how a small-angle tilt boundary is formed by an array of edge
dislocations.
14. Describe the arrangement of atoms in the vicinity of a twin boundary.
15. Define the terms microstructure and microscopy.
16. Explain what preparations are necessary for observation of the grain
structure of a polycrystalline material with an optical microscope.
17. Name and briefly describe the operations of each of the two types of
electron microscopes.
18. In general terms, briefly explain how scanning probe microscopes operate.
19. Given a photomicrograph of a polycrystalline material, as well as the
magnification, determine the grain size using intercept and ASTM
methods.
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CHAPTER 5
DIFFUSION
LEARNING OBJECTIVES
1. Give a brief definition of diffusion.
2. Explain the terms interdiffusion and self-diffusion.
3. (a) List and briefly describe the two atomic mechanisms of diffusion.
(b) Indicate which type of diffusion occurs more rapidly, and then explain why
this is so.
4. Given the mass of material diffusing through a cross-sectional area over a
specified time period, compute the diffusion flux.
5. Define the terms concentration profile and concentration gradient.
6. Make a distinction between steady-state and nonsteady-state diffusion.
7. For steady-state diffusion through a metal sheet, determine the diffusion flux
given values for the diffusion coefficient, the sheet thickness, and the
concentrations of diffusing species at both surfaces.
8. Cite the driving force for steady-state diffusion.
9. Write Fick's second law in equation form.
10. For diffusion into a semi-infinite solid and when the concentration of
diffusing species at the surface is held constant, compute the concentration
at some position after a specified time given the following:
(a) the pre-diffusion concentration in the solid,
(b) the surface composition, and
(c) the value of the diffusion coefficient of the diffusing species.
Also, assume that a tabulation of error function values (similar to Table 5.1)
is available.
11. Cite two factors that influence diffusion rate (i.e., the magnitude of the
diffusion coefficient).
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12. Given the pre-exponential, Do, the activation energy, the absolute
temperature, and the gas constant, be able to compute the value of the
diffusion coefficient.
13. Given a plot of logarithm of the diffusion coefficient (to the base 10) versus
the reciprocal of absolute temperature, determine values for the diffusion
coefficient's pre-exponential and activation energy.
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CHAPTER 6
MECHANICAL PROPERTIES OF METALS
LEARNING OBJECTIVES
1. List three factors that should be considered in designing laboratory tests to
assess the mechanical characteristics of materials for service use.
2. Given the tensile load on a specimen and its original and instantaneous
cross-sectional dimensions, be able to compute the engineering stress
and the true stress.
3. Given the original and instantaneous lengths of a specimen which is being
loaded in tension, be able to compute the engineering strain and the true
strain.
4. Given the magnitude of a tensile stress that is applied parallel to the
specimen axis, compute the magnitudes of normal and shear stresses on a
plane that is oriented at some specified angle relative to the specimen
end-face.
5. Distinguish between elastic and plastic deformations, both by definition, and
in terms of behavior on a stress-strain plot.
6. Compute the elastic modulus from a stress-strain diagram.
7. Given the elastic modulus and either elastic engineering stress or strain, be
able to compute the other (strain or stress).
8. For a material that exhibits nonlinear elastic behavior, be able to compute
tangent and secant moduli from its stress-strain diagram.
9. State what is occurring on an atomic level as a material is elastically
deformed.
10. Briefly explain how the shape of a material's force versus interatomic
separation curve influences its modulus of elasticity.
11. Given the cross-sectional area of a specimen over which a shear forced of
specified magnitude acts, and, in addition, the resulting shear strain, be
able to compute the shear modulus.
12. Define anelasticity.
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13. Given Poisson's ratio and the elastic strain in the direction of the applied
load (i.e., axial strain), be able to compute the elastic strain in the lateral (or
perpendicular) direction.
14. Cite typical value ranges of modulus of elasticity and Poisson's ratio for
metallic materials.
15. Given values of modulus of elasticity and Poisson's ratio for an isotropic
material, estimate the value of its shear modulus.
16. Given an engineering stress-strain diagram estimate the proportional limit,
and then determine the yield strength (0.002 strain offset) and the tensile
strength.
17. Schematically sketch the stress-strain behavior for a material that displays
distinct upper and lower yield points, and then explain how the yield
strength is determined.
18. Given the stress-strain behavior for two metals, be able to distinguish which
is stronger.
19. For a cylindrical specimen of a ductile material that is deformed in tension,
describe how the specimen's profile changes in moving through elastic
and plastic regimes of the stress-strain curve, to the point of fracture.
20. Explain why engineering stress decreases with increasing engineering
strain past the tensile strength point.
21. Cite typical yield and tensile strength ranges for metal alloys.
22. Give a brief definition of ductility, and schematically sketch the engineering
stress-strain behaviors for both ductile and brittle materials.
23. Given the original and fracture dimensions of a specimen deformed in
tension, be able to determine its ductility in terms of both percent
elongation and percent reduction of area.
24. Cite which tensile parameters are sensitive (and also which are insensitive)
to any prior deformation, the presence of impurities, and/or any heat
treatment.
25. For metallic materials cite how elastic modulus, tensile and yield strengths,
and ductility change with increasing temperature.
26. Give brief definitions of and the units for modulus of resilience and
toughness (static).
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27. Given yield strength and modulus of elasticity values for some material,
compute its modulus of resilience.
28. Given the stress-strain behavior for two metals, determine which is the most
resilient and which is the toughest.
29. Given values of the constants K and n in the equation relating plastic true
stress and true strain, be able to compute the true stress necessary to
produce some specified true strain.
30. Schematically plot both the tensile engineering stress-strain and true
stress-strain behaviors for the same material and then explain the
difference between the two curves.
31. Describe the phenomenon of elastic recovery using a stress-strain plot.
32. Determine the elastic strain recovered for some material, given its stress-
strain plot and the total strain to which a specimen has been subjected.
33. Define hardness in a one- or two-sentence statement.
34. Cite three reasons why hardness tests are performed more frequently than
any other mechanical test on metals.
35. Name the two most common hardness-testing techniques that are used in
the U.S., and give two differences between them.
36. Name and briefly describe the two different microhardness testing
techniques. Now cite situations for which these techniques are generally
used.
37. Cite three precautions that should be taken when performing hardness
tests in order to insure accurate readings.
38. Schematically diagram tensile strength versus hardness for a typical metal.
39. Cite five factors that can lead to scatter in measured data.
40. Given a series of data values that have been collected, be able to compute
both the average and the standard deviation.
41. Given the yield strength of a ductile material, be able to compute the
working stress.
42. Briefly describe how the strength performance index for a solid cylindrical
shaft is determined.
43. Explain the manner in which materials selection charts are employed in the
materials selection process.
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CHAPTER 7
DISLOCATIONS AND STRENGTHENING MECHANISMS
LEARNING OBJECTIVES
1. Describe edge dislocation motion by the translation of an extra half-plane of
atoms as atomic bonds are repeatedly and successively broken and then
reformed.
2. Briefly describe how plastic deformation occurs by the movement of both
edge and screw dislocations in response to applied shear stresses.
3. Distinguish between edge and screw dislocations in terms of the direction of
line motion in response to an applied shear stress.
4. Define dislocation density and cite its units.
5. Given a drawing of atom positions around an edge dislocation, locate
regions of compressive and tensile strains that are created in the crystal
due to the presence of the dislocation.
6. Name and describe the kind of lattice strains that are found in the vicinity of a
screw dislocation.
7. Define slip system.
8. Specify the characteristics of a slip system for some crystal structure.
9. Specify the slip systems for face-centered cubic and body-centered cubic
crystal structures.
10. Explain, in terms of slip systems, why body-centered cubic and hexagonal
close-packed metals ordinarily experience a ductile-to-brittle transition with
decreasing temperature, while face-centered cubic metals do not
experience such a transition.
11. Define resolved shear stress and critical resolved shear stress.
12. Compute the resolved shear stress on a specified plane given the value of
the applied tensile stress, as well as 1) the angle between the normal to
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the slip plane and the applied stress direction, and 2) the angle between
the slip and stress directions.
13. Describe the nature of plastic deformation, in terms of dislocation motion,
for a single crystal that is pulled in tension.
14. Briefly explain how the grain structure of a polycrystalline metal is altered
when it is plastically deformed.
15W. Briefly describe, from an atomic perspective, how plastic deformation
results from the formation of mechanical twins.
16W. Cite two differences between deformation by slip and deformation by
twinning.
17. Explain why and describe how the yield strength of a metal is related to the
ability of dislocations to move.
18. Describe how grain boundaries impede dislocation motion and why a metal
having small grains is stronger than one having large grains.
19. Given a plot of yield strength versus d -1/2 (d being the average grain size),
be able to determine the values of σo and ky, and also the yield strength at
a specified value of d.
20. Briefly describe the phenomenon of solid-solution strengthening.
21. Briefly explain solid-solution strengthening for substitutional impurity atoms
in terms of lattice strain interactions with dislocations.
22. Describe the phenomenon of strain hardening (or cold-working) in terms of
1) changes in mechanical properties, and 2) stress-strain behavior.
23. Given the original and deformed cross-sectional dimensions of a metal
specimen that has been cold-worked, compute the percent cold work.
24. Schematically plot tensile strength, yield strength, and ductility versus
percent cold work for a metal specimen.
25. Briefly describe the phenomenon of strain hardening in terms of
dislocations and strain field interactions.
26. Cite three characteristics/properties that become altered when a metal is
plastically deformed.
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27. Briefly describe the changes that take place as a metal experiences
recovery.
28. Briefly describe what occurs during the process of recrystallization, in terms
of both the alteration of microstructure and mechanical characteristics of
the material.
29. Cite the driving force for recrystallization.
30. Make a schematic plot of how the room temperature tensile strength and
ductility vary with temperature (at a constant heat-treating time) in the
vicinity of the recrystallization temperature, for a metal that was previously
cold-worked.
31. Define recrystallization temperature.
32. Name two factors that influence the recrystallization temperature of a metal
or alloy, and then note how they influence the recrystallization
temperature.
33. Make a distinction between hot-working and cold-working.
34. Describe a procedure that may be used to reduce the cross-sectional area
of a cylindrical specimen, given its original and deformed radii, and, in
addition, the required strength and ductility after deformation.
35. Describe the phenomenon of grain growth from both microscopic and
atomic level perspectives.
36. Cite the driving force for grain growth.
37. For some polycrystalline material, given a value for the diameter exponent
(n), and, in addition, the grain diameters at two different times at an
elevated temperature, be able to compute the following: 1) the original
grain diameter, and 2) the grain diameter after yet another time.
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CHAPTER 8
FAILURE
LEARNING OBJECTIVES
1. Cite the three usual causes of failure.
2. (a) Cite the two modes of fracture and the differences between them.
(b) Note which type of fracture is preferred, and give two reasons why.
3. Describe the mechanism of crack propagation for both ductile and brittle
modes of fracture.
4. Describe the two different types of fracture surfaces for ductile metals, and,
for each, cite the general mechanical characteristics of the material.
5. Briefly describe the mechanism of crack formation and growth in moderately
ductile materials.
6. Briefly describe the macroscopic fracture profile for a material that has failed
in a brittle manner.
7. Name and briefly describe the two crack propagation paths for
polycrystalline brittle materials.
8. Explain why the strengths of brittle materials are much lower than predicted
by theoretical calculations.
9. Given the magnitude of an applied tensile stress, and the length and tip
radius of a small crack which axis is perpendicular to the direction of the
applied stress, compute the maximum stress that may exist at the crack tip.
10. Cite the conditions that must be met in order for a brittle material to
experience fracture.
11. Briefly state why sharp corners should be avoided in designing structures
that are subjected to stresses.
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12. For some material, given values of the modulus of elasticity and specific
surface energy, and the length of an internal crack, be able to compute the
critical stress for propagation of this crack.
13W. Define critical strain energy release rate, and cite an equation for its
determination.
14. Describe/illustrate the three different crack displacement modes.
15. Describe the conditions of plane stress and plane strain.
16. In a brief statement define fracture toughness and also specify its units.
17W. Make distinctions between stress intensity factor, fracture toughness, and
plane strain fracture toughness.
18W. Given plane strain fracture toughness and yield strength values for a
material, compute the minimum plate thickness for the condition of plane
strain.
19. Given the plane-strain fracture toughness of a material, the length of the
longest surface crack, and the value of Y, compute the critical (or design)
stress.
20. Determine whether or not a flaw of critical length is subject to detection
given the resolution limit of the detection apparatus, the maximum applied
tensile stress, the plane strain fracture toughness of the material, as well as
a value for the scale parameter (Y).
21. Name three factors that are critical relative to a metal experiencing a
transition from ductile to brittle fracture.
22. Name and briefly describe the two techniques that are used to measure
impact energy (or notch toughness) of a material.
23. Make a schematic plot of the dependence of impact energy on temperature
for a metal that experiences a ductile-to-brittle transition.
24. Note which types of materials do, and also those which do not, experience
a ductile-to-brittle transition with decreasing temperature.
25. Cite two measures that may be taken to lower the ductile-to-brittle transition
temperature in steels.
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26. Define fatigue and specify the conditions under which it occurs.
27. Name and describe the three different stress-versus-time cycle modes that
lead to fatigue failure.
28. Given a sinusoidal stress-versus-time curve, be able to determine the stress
amplitude and mean stress.
29. (a) Briefly describe the manner in which tests are performed to generate a
plot of fatigue stress versus the logarithm of the number of cycles.
(b) Note three in-service conditions should be replicated in a fatigue test.
30. Schematically plot the fatigue stress as a function of the logarithm of the
number of cycles to failure for both materials which do and which do not
exhibit a fatigue limit. For the former, label the fatigue limit.
31. Given a fatigue plot for some material:
(a) for some particular stress level, determine the maximum number of cycles
allowable before failure (i.e., the fatigue lifetime);
(b) for some specified number of cycles, determine the fatigue strength.
32W. Briefly describe the two stages of crack propagation in polycrystalline
materials which may ultimately lead to fatigue failure.
33. Describe the two differently types of fatigue surface features, and cite the
conditions under which they occur.
34W. Given σmax and σmin, and, for a particular material, initial and critical crack
lengths, and, in addition, values for the Y, A , and m parameters, estimate
the fatigue lifetime.
35. Cite five measures that may be taken to improve the fatigue resistance of a
metal.
36. Describe thermal fatigue failure, and note how it may be prevented.
37. Describe corrosion fatigue, and then cite five measures that may be taken
to prevent it.
38W. Briefly describe the steps that are used to ascertain whether or not a
particular metal alloy is suitable for use in an automobile valve spring.
39. Define creep and specify the conditions under which it occurs.
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40. Make a schematic sketch of a typical creep curve, and then note on this
curve the three different creep stages.
41. Given a creep plot for some material, determine (a) the steady-state creep
rate, and (b) the rupture lifetime.
42. Given the absolute melting temperature of a metal, estimate the
temperature at which creep becomes important.
43. Schematically sketch how the creep behavior of a material changes with
increasing temperature and increasing load (or stress).
44. Make schematic plots showing how the rupture life and steady-state creep
rate for a material are represented as functions of stress and temperature.
45. Cite the general mathematical expression for the dependence of steady-
state creep rate on both applied stress and temperature.
46W. Given a Larson-Miller master plot of creep data for some material,
determine the rupture life at a given temperature and stress level.
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CHAPTER 9
PHASE DIAGRAMS
LEARNING OBJECTIVES
1. Define phase.
2. Name three important microstructural characteristics for multiphase alloys.
3. Cite three factors that affect the microstructure of an alloy.
4. Briefly explain the concept of phase equilibrium.
5. Briefly define metastable in terms of microstructure.
6. (a) Schematically sketch simple isomorphous and eutectic phase diagrams.
(b) On these diagrams label the various phase regions.
(c) Also label liquidus, solidus, and solvus lines.
7. Given a binary phase diagram, the composition of an alloy, its temperature,
and assuming that the alloy is at equilibrium, determine:
(a) what phase(s) is (are) present;
(b) the composition(s) of the phase(s); and
(c) the mass fraction(s) of the phase(s).
8. Given mass fractions and densities for both phases of a two-phase alloy,
determine the phase volume fractions.
9. Using an isomorphous phase diagram, explain the phenomenon of coring
for the nonequilbrium solidification of an alloy that belongs to this
isomorphous system.
10. Given a binary phase diagram, locate the temperatures and compositions
of all eutectic reactions, and then write the reactions for either heating or
cooling.
11. Given a binary eutectic phase diagram, for an alloy of specified composition
the microstructure of which consists of both primary and eutectic
microconstituents, do the following:
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(a) compute the mass fractions of both microconstituents; and
(b) sketch and label a schematic drawing of the microstructure.
12. Define microconstituent, and then cite two examples.
13. Given a binary phase diagram, determine the solubility limit of one of the
elements in one phase at some given temperature.
14. Explain the following terms: (a) terminal solid solution, (b) intermediate
solid solution, and (c) intermetallic compound.
15. For some given binary phase diagram, do the following:
(a) locate the temperatures and compositions of all eutectoid, peritectic, and
congruent phase transformations; and
(b) write reactions for all these transformations for either heating or cooling.
16W. Write the Gibbs phase rule in its most general form, and explain each
term in the phase rule equation.
17W. Apply Gibbs phase rule in single- and two-phase regions, as well as on
isotherm lines for binary phase diagrams.
18. Name the crystal structures for both ferrite (α-iron) and austenite (γ-iron).
19. Give the composition of iron carbide, Fe3C, and also the maximum
solubility of carbon in both α-ferrite and austenite phases.
20. Specify the temperature and composition at which the eutectoid reaction
occurs, and write this eutectoid reaction for either heating or cooling.
21. Cite the three types of ferrous alloys on the basis of carbon content, and
then note the composition range for each.
22. Briefly describe the pearlite structure, and then calculate the relative
amounts of the two phases in this structure.
23. Given the composition of an iron-carbon alloy containing between 0.022
wt% C and 2.11 wt% C, be able to
(a) determine whether it is a hypoeutectoid or hypereutectoid alloy;
(b) specify the proeutectoid phase;
(c) compute the mass fractions of the proeutectoid phase and pearlite; and
(d) make a schematic diagram of the microstructure.
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24. Given the composition of an Fe-C-M alloy (where M represents a metallic
element other than iron--e.g., Cr, Ni, Mo, etc.), and a plot of the eutectoid
composition versus the concentration of element M, be able to determine
(a) the proeutectoid phase, and (b) the approximate mass fractions of
proeutectoid and pearlite microconstituents.
24
CHAPTER 10
PHASE TRANSFORMATIONS IN METALS
LEARNING OBJECTIVES
1. Cite the two distinct steps that are involved in the formation of particles of a
new phase.
2W (a) For nucleation, make a schematic plot of change in free energy versus
nucleus radius, and on this plot label the critical radius and the activation
free energy.
(b) On this same plot sketch another schematic curve for nucleation at a
higher temperature.
3W (a) Cite the difference between homogeneous nucleation and
heterogeneous nucleation.
(b) Sketch and label on the same plot, schematic free energy-versus-
nucleus radius curves for both homogeneous and heterogeneous
nucleation.
4W (a) Sketch and label on the same plot, schematic nucleation rate-versus-
temperature curves for both homogeneous and heterogeneous nucleation.
(b) Now, for each curve, indicate the degree of supercooling.
5W. On a single plot, sketch and label schematic nucleation rate-versus-
temperature, growth rate-versus-temperature, and overall reaction rate-
versus-temperature curves.
6. Make a schematic fraction transformation-versus-logarithm of time plot for a
typical solid-solid transformation, and then note nucleation and growth
regions on the curve.
7. For some solid-solid reaction, given values of the constants k and n, compute
the fraction transformation after a specified time.
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8. Given a fraction transformation-versus-logarithm of time curve at some
temperature, be able to determine the overall rate of the transformation.
9. Define the terms supercooling and superheating.
10. Explain how an isothermal transformation diagram for some alloy is
generated from a series of isothermal fraction transformation-versus-
logarithm of time curves.
11. Describe the difference in microstructure for fine and coarse pearlites, and
then explain this difference in terms of the isothermal temperature range
over which each transforms.
12W. Briefly describe the microstructures of upper and lower bainites and of
spheroidite.
13. Briefly describe martensite in terms of its crystal structure and its
microstructures.
14. Describe the difference between thermally activated and athermal
transformations, and then cite one example of each transformation.
15. Describe the heat treatment that is necessary to produce martensite, and
explain why it forms instead of pearlite or bainite.
16. Given the isothermal transformation diagram for some iron-carbon alloy
and also a specific isothermal heat treatment, be able to describe the
microstructure that will result. The microstructure may consist of austenite,
a proeutectoid phase, fine pearlite, coarse pearlite, spheroidite, bainite,
and/or martensite.
17. Given a continuous cooling transformation diagram for some particular
alloy and a specific cooling curve, describe the resulting microstructure
that exists at room temperature.
18. Define what is meant by the critical cooling rate, and given a continuous
cooling transformation diagram, schematically plot the critical cooling
curve.
19. Describe or diagram how alloying elements other than carbon alter the
continuous cooling transformation diagram for a steel. Now explain, in
26
terms of this alteration, why alloying elements make a steel more "heat-
treatable."
20. Schematically diagram how tensile strength, hardness, and ductility vary
with carbon content for steels having microstructures consisting of fine and
coarse pearlite, and spheroidite. Also, explain why hardness and strength
increase with increasing carbon content.
21. Explain briefly why fine pearlite is harder than coarse pearlite, which in turn
is harder than spheroidite.
22. Qualitatively compare the mechanical characteristics of bainite and iron-
carbon alloys that have other microstructures.
23. Cite two reasons why martensite is so hard and brittle.
24. Describe the microstructure of tempered martensite.
25. Describe the heat treatment that is necessary to produce tempered
martensite.
26. Compare the properties of martensite and tempered martensite, and also
explain the properties of tempered martensite in terms of its microstructure.
27. Schematically plot how hardness depends on tempering time at constant
temperature, and briefly explain this behavior.
28. Schematically plot how yield strength, tensile strength, and ductility depend
on tempering temperature (at constant tempering time), and then explain
this behavior.
29. (a) Describe the phenomenon of temper embrittlement.
(b) Note what procedures cause it to occur.
(b) List measures that may be taken to prevent it.
30. Describe briefly and qualitatively the procedure necessary to transform one
steel microstructure into another (e.g., bainite to spheroidite).
27
CHAPTER 11
APPLICATIONS AND PROCESSING OF METAL ALLOYS
LEARNING OBJECTIVES
1. Cite three reasons why ferrous alloys are used extensively as engineering
materials, and also three of their major limitations.
2. Define what is meant by a plain carbon steel, and cite three typical
applications.
3. Recognize the four digit AISI/SAE designation for both plain carbon and low
alloy steels, and from such determine the carbon content.
4. Name three other types of steels and, for each, cite compositional
differences, distinctive properties, and typical uses.
5. Specify the three classes of stainless steels.
6. Cite two differences between cast irons and steels.
7. (a) Name the four major cast iron types.
(b) For each type draw and label a schematic diagram of the microstructure,
and give a general description of its mechanical characteristics.
8. Cite the distinguishing features for both wrought and cast alloys.
9. Name seven different types of nonferrous alloys, and for each, cite its
distinctive physical and mechanical characteristics, and, in addition, list at
least three typical applications.
10. (a) Name and describe four forming operations that are used to shape
metal alloys.
(b) Cite the general mechanical characteristics of materials that are
subjected to these forming operations.
11. (a) Name and describe four casting techniques.
(b) Cite three circumstances for which casting is the preferred fabrication
mode.
28
12. Describe the powder metallurgical forming process, and note two reasons
why it is used.
13. (a) Briefly describe the process of welding, and note reasons why it is
used.
(b) Cite four potential problems that may be encountered with the formation
of a heat affected zone in the vicinity of a weld junction.
14. State the purposes of and describe the procedures for the following heat
treatments: process annealing, stress relief annealing, normalizing, full
annealing, and spheroidizing.
15. Define hardenability.
16. Describe the Jominy end-quench test.
17. Make a schematic sketch of a typical hardenability curve (label both vertical
and horizontal axes), and then briefly explain the shape of the curve.
18. (a) On the same plot, schematically sketch hardenability curves for two
different alloys--one of which is more hardenable than the other.
(b) Explain the difference in shape of these two curves.
19. For the quenching of a steel specimen, briefly explain why quenching
medium type and degree of agitation influence the rate of specimen
cooling.
20. Generate a hardness profile for a cylindrical steel specimen that has been
austenitized and then quenched, given the hardenability curve for the
specific alloy, as well as quenching rate-versus-bar diameter curves at
several radial positions for the quenching medium used.
21. Using a phase diagram, describe the two heat treatments (solution and
precipitation) that are involved in the precipitation hardening of a binary
alloy. Explain why each heat treatment is carried out and describe
changes in microstructure that occur during each heat treatment.
22. (a) Schematically plot how the room temperature yield and tensile
strengths, and hardness depend on the logarithm of time for a precipitation
heat treatment at constant temperature.
29
(b) Explain the general shape of these curves in terms of the mechanism of
precipitation hardening (i.e., dislocation-precipitate particle interactions).
23. Cite two necessary requirements for an alloy to be precipitation
hardenable.
30
CHAPTER 12
STRUCTURES AND PROPERTIES OF CERAMICS
LEARNING OBJECTIVES
1. Make a distinction between cations and anions.
2. Cite two features of the component ions that determine the crystal structure of
a ceramic material.
3. Sketch (or describe) unit cells for sodium chloride, cesium chloride, zinc
blende, fluorite, and perovskite crystal structures.
4. Given the chemical formula for a ceramic compound, the ionic radii of its
component ions, and, using Table 12.4, determine the crystal structure.
5. For a ceramic material which crystal structure may be generated from the
stacking of close-packed planes of anions, given which type of interstitial
positions (tetrahedral or octahedral) are occupied with cations, do the
following:
(a) specify what fraction of these sites are filled, and
(b) note the occupied interstitial positions between two close-packed planes
drawn as stacked one upon the other.
6. For an ionic compound having one of the crystal structures discussed in this
chapter, be able to compute its density given the atomic weights of the
constituent elements, the unit cell edge length, and Avogadro's number.
7. Given the unit cell for some ceramic crystal structure, be able to sketch the
ionic/atomic packing of a specified crystallographic plane.
8. Draw and describe the basic structural unit for the silicate ceramics.
9. Schematically diagram the atomic structure of a silica glass.
10. Sketch (or describe) the following:
(a) a unit cell for the diamond cubic crystal structure,
(b) the atomic structure of graphite,
31
(c) the structure of a C60 fullerene molecule, and
(d) the structure of a carbon nanotube.
11. Name and describe eight different ionic point defects that are found in
ceramic compounds (including Schottky and Frenkel defects).
12. Define the term electroneutrality, and note what part it plays in the formation
of ionic point defects in ceramic materials.
13. Define stoichiometric, and cite one example of a nonstoichiometric material.
14. Note two ways in which an ionic compound can be made to be
nonstoichiometric.
15. (a) Given a substitutional impurity ion, determine whether or not it will
render an ionic compound nonstoichiometric.
(b) If the host material does become nonstoichiometric, ascertain what
kind(s) of defect(s) form, and how many form for every substitutional
impurity ion.
16. Note three requirements that must be met in order for there to be significant
solid solubility of one ionic compound in another.
17. Note one difference in diffusion mechanism for ionic ceramics and for
metals.
18. Cite the differences in room temperature mechanical characteristics for
metals and ceramics.
19. Briefly explain why there is normally significant scatter in the fracture
strength for identical specimens of the same ceramic material.
20. Note the reason why ceramic materials are stronger in compression than in
tension.
21. Give three reasons why the stress-strain characteristics of ceramic
materials are determined using transverse bending tests rather than
tensile tests.
22. Given the cross-sectional dimensions of a rectangular ceramic rod bent to
fracture using a three-point loading technique, as well as the distance
32
between support points, and the fracture load, compute the flexural
strength.
23. Given the radius of a cylindrical ceramic rod that is bent to fracture using a
three-point loading technique, as well as the distance between support
points, and the fracture load, compute the flexural strength.
24. Briefly describe the mechanism by which plastic deformation occurs for
each of crystalline and noncrystalline ceramic materials.
25. On the basis of slip considerations, briefly explain why crystalline ceramic
materials are so brittle.
26. Briefly define viscosity and cite the units in which it is expressed.
27. For a porous ceramic, do the following:
(a) Given the modulus of elasticity for the nonporous material, compute E for
a specified volume fraction of porosity.
(b) Given values of the experimental σo and n constants, calculate the
flexural strength at some given P.
33
CHAPTER 13
APPLICATIONS AND PROCESSING OF CERAMICS
LEARNING OBJECTIVES
1. List the three primary ingredients of a soda-lime glass.
2. Cite the two prime assets of glass materials.
3. Define devitrification.
4. (a) Briefly describe the process by which glass-ceramics are produced.
(b) Note two properties of these materials that make them superior to glass.
5. Name the two types of clay products, and then give two examples of each.
6. For the refractory ceramics do the following:
(a) Cite three important requirements that normally must be met by this group
of materials.
(b) For each of the four classifications discussed, cite the primary ingredients
and typical applications.
7. For the abrasive ceramics do the following:
(a) Cite three important requirements that normally must be met by this group
of materials.
(b) Name four different ceramic materials that are commonly used as
abrasives.
(c) Cite the three different forms of abrasives.
8. Briefly describe the process by which portland cement is produced.
9. Briefly explain the mechanism by which cement hardens when water is
added.
10. Briefly explain the role of cement in a concrete mix.
11. List three advanced ceramics applications, and, for each, note its important
characteristics and/or the function(s) it performs.
34
12 (a) Schematically plot specific volume versus temperature for both
crystalline and noncrystalline ceramics.
(b) On this graph indicate melting and glass-transition temperatures.
13. (a) Schematically sketch a plot of the temperature dependence of the
viscosity of a glass.
(b) Now note how the curve changes with increasing impurity additions.
14. Name and briefly describe four forming methods that are used to fabricate
glass pieces.
15. Briefly explain why thermal stresses are established in glass pieces as they
are cooled.
16. (a) Briefly describe the procedure that is used to thermally temper glass
pieces.
(b) Now explain the mechanism by which thermal tempering increases
strength.
17. Cite the two roles that clay minerals play in the fabrication of ceramic
bodies.
18. Name and briefly describe the two techniques that are used to fabricate
clay products.
19. Briefly explain what processes occur during the drying and firing of clay-
based ceramic ware.
20. (a) Define vitrification.
(b) Note the role this process plays in the development of strength of a
ceramic body.
21. Name and briefly describe the three ceramic powder pressing techniques
that were discussed in this chapter.
22. Briefly describe and diagram the process of sintering as it occurs for
powder particle aggregates.
23. Describe the tape casting process.
35
CHAPTER 14
POLYMER STRUCTURES
LEARNING OBJECTIVES
1. Define the term isomerism.
2. Describe a typical polymer molecule in terms of its chain structure, and, in
addition, how the molecule may be generated by repeating mer units.
3. Draw mer structures for polyethylene, polyvinyl chloride, polytetra-
fluoroethylene, polypropylene, and polystyrene.
4. Distinguish between a homopolymer and a copolymer.
5. Distinguish between bifunctional and trifunctional mer units.
6. For some homopolymer, given its mer chemical formula, its several
molecular weight ranges, and, for each range, the number and weight
fractions, be able to compute:
(a) the number-average and weight-average molecular weights, and
(b) the number-average and weight-average degrees of polymerization.
7. For a copolymer, given its mer chemical formulas, the atomic weights of the
constituent atoms, and the fraction of each mer type, be able to compute
the average mer molecular weight.
8. Cite two features of polymer chains that restrict their ability to rotate and
bend.
9. Name and briefly describe the four general types of molecular structures
found in polymers.
10. Distinguish between head-to-tail and head-to-head configurations.
11. Name and briefly describe:
(a) the three types of stereoisomers,
(b) the two kinds of geometrical isomers, and
(c) the four types of copolymers.
12. Name the two classifications of polymeric materials according to their
mechanical characteristics at elevated temperatures.
36
13. Cite the differences in behavior for thermoplastic and thermosetting
polymers, and also the differences in their molecular structures.
14. Draw the following chemical repeat units: acrylonitrile, butadiene,
chloroprene, cis-isoprene, isobutylene, and dimethylsiloxane.
15. (a) Briefly describe the crystalline state in polymeric materials.
(b) Cite the main difference between the crystalline state in polymers and in
metallic materials.
16. Given the density of a polymer specimen, as well as densities for totally
crystalline and totally amorphous materials of the same polymer, be able to
compute the percent crystallinity.
17. Cite how the degree of crystallinity in a polymer material is affected by
polymer chemistry, by characteristics of the polymer structure, and for the
various copolymers.
18. Briefly describe the structure of a chain-folded polymer crystallite.
19. Briefly describe and diagram the spherulitic structure for a semicrystalline
polymer.
20. Note one difference in diffusion mechanism for polymers and for metals.
37
CHAPTER 15
CHARACTERISTICS, APPLICATIONS, AND PROCESSINGOF POLYMERS
LEARNING OBJECTIVES
1. (a) Schematically plot the three different characteristic types of stress-strain
behavior for polymeric materials.
(b) Now note which type(s) of polymer(s) display(s) each of these behaviors.
2. Make a comparison of the general mechanical properties of plastics and
elastomeric materials with metals and ceramics.
3. Cite three effects on the mechanical characteristics of a polymer as its
temperature is increased, or as the deformation strain rate is decreased.
4. (a) Describe the macroscopic tensile deformation (i.e., specimen profile) of a
cylindrical dog-bone specimen of a typical ductile plastic to fracture.
(b) Correlate this behavior with the stress-strain plot.
5. Define viscoelasticity.
6. (a) Describe the manner in which stress relaxation measurements are
conducted.
(b) Using the results of a stress relaxation test, briefly explain how the
relaxation modulus is determined.
7. (a) On a graph of the logarithm of relaxation modulus versus temperature
plot schematic curves for semicrystalline, amorphous, and crosslinked
polymers.
(b) On this plot note melting and glass transition temperatures.
(c) In addition, indicate on this same plot glass, leathery, rubbery, and
viscous flow regions.
8. (a) Briefly describe the phenomenon of crazing.
(b) Note which type of polymers craze.
(c) Cite experimental/service conditions that produce crazing in polymeric
materials.
9. Briefly describe the mechanism by which semicrystalline polymers elastically
deform.
38
10. Describe/sketch various stages in the plastic deformation of a
semicrystalline (spherulitic) polymer.
11. Briefly describe the effects of annealing on a semicrystalline polymer that
has been permanently deformed.
12. Discuss the influence of the following factors on polymer tensile modulus
and/or strength:
(a) molecular weight,
(b) degree of crystallinity,
(c) extent of crosslinking,
(d) predeformation, and
(e) the heat treating undeformed materials.
13. (a) Briefly describe the molecular mechanism by which elastomeric
polymers deform elastically.
(b) Now cite the driving force for the recoil of an elastomeric material.
14. Note the four criteria that are necessary for a polymer to exhibit elastomeric
behavior.
15. Briefly describe the vulcanization process and what effect it has on the
mechanical characteristics of elastomeric materials.
16. Briefly describe, from a molecular perspective,
(a) crystallization,
(b) melting, and
(c) the glass transition for polymeric materials.
17. For polymer crystallization, given values of the constants k and n, compute
the fraction crystallization after a specified time.
18. Schematically plot specific volume versus temperature for crystalline,
semicrystalline, and amorphous polymers, noting glass-transition and
melting temperatures.
19. (a) List four characteristics or structural components of a polymer that affect
its melting temperature.
(b) Note the manner in which each characteristic/component influences themagnitude of Tm.
20. (a) List six characteristics or structural elements of a polymer that influence
its glass transition temperature.
39
(b) Now note how each of these characteristics/elements affects themagnitude of Tg.
21. (a) Cite the seven different polymer application types.
(b) Note the general characteristics of each of these types.
22. Schematically sketch the structure of a silicone mer.
23. (a) Cite important properties that are normally required for polymers that
are drawn into fibers.
(b) Note common applications for polymeric fibers.
24. For each of ultrahigh molecular weight polyethylene, the liquid crystal
polymers, and the thermoplastic elastomers do the following:
(a) Describe salient structural characteristics;
(b) Cite critical and unique properties; and
(c) List at least four typical applications.
25. Briefly describe the mechanisms by which chain reaction and step reaction
polymerization processes occur.
26. Name the five types of polymer additives, and, for each, how it modifies the
properties.
27. Name and briefly describe the five fabrication techniques used for plastic
polymers (that were discussed in this chapter).
28. Briefly describe forming/processing techniques that are typically employed
in the fabrication of fibers and films.
40
CHAPTER 16
COMPOSITES
LEARNING OBJECTIVES
1. Define composite in the context of this chapter's discussion.
2. Name the terms that are used to describe the phases in most two-phase
composites.
3. Name the three main divisions of composite materials, and cite the
distinguishing feature of each.
4. Cite the difference in strengthening mechanism for large-particle and
dispersion-strengthened particle-reinforced composites.
5. For a large-particle composite, given the elastic moduli of matrix and particle
phases as well as the volume fraction of each phase, compute both upper
and lower limits of the elastic modulus.
6. Cite one example each of large-particle and dispersion-strengthened
composites.
7. Briefly note the distinction between cement and concrete.
8. Cite three ways in which the strength of concrete may be improved by
reinforcement.
9. Given the elastic modulus, tensile strength, and density (in grams per cubic
centimeter) of a material, compute its specific stiffness and specific
strength.
10. Given fiber strength and diameter, and magnitudes of the fiber-matrix
interfacial bond and shear yield strength, determine the critical fiber length
for effective reinforcement.
11. Make the distinction between continuous and discontinuous fibers.
12. Make a schematic sketch of the load sustained by a fiber as a function of
position along the fiber length for (a) a fiber of critical length, and (b) a fiber
of length greater than the critical.
13. (a) Name the three different types of fiber-reinforced composites on the
basis of fiber length and orientation.
41
(b) Comment on the distinctive mechanical characteristics for each of these
three composite types.
14. Make a schematic plot of stress versus strain, and include curves for the
following:
(a) fiber and matrix phases that have mechanical properties typical of those
used for fibrous composites; and
(b) a composite that consists of these continuous and aligned fibers
embedded in this matrix material, and for which loading is in the
longitudinal direction.
15. For an aligned and continuous fiber-reinforced composite, given volume
fractions and elastic moduli of fiber and matrix phases, be able to compute
the elastic modulus in both longitudinal and transverse directions.
16. Compute the longitudinal strength for a continuous and aligned fibrous
composite given values for fiber strength, matrix stress at fiber failure, and
fiber volume fraction.
17. For a discontinuous and aligned fibrous composite, compute thelongitudinal strength for (a) lc < l < 15lc and (b) l < lc, given the following
values: fiber strength, critical and actual fiber lengths, matrix stress at fiber
fracture, fiber-matrix bond strength, and shear yield strength of the matrix
phase.
18. Compute the strength of a discontinuous and randomly oriented fibrous
composite, given values for the fiber efficiency parameter, elastic moduli
for fiber and matrix phases, as well as phase volume fractions.
19. Be able to cite the three classes of fibers, and, for each, the distinctive
characteristics and at least two examples (i.e., materials).
20. Cite three functions that the matrix phase serves for fiber-reinforced
composites.
21. (a) Cite the three classifications of polymer-matrix composites (according to
fiber-reinforcement material).
(b) For each classification, cite the principal desirable characteristics and
limitations.
(c) Note at least three common applications for each of these PMC types.
22. For metal-matrix composite materials
(a) list the most commonly used matrix and fiber materials, and
42
(b) cite the main advantages of these materials over the PMCs.
23. Note the primary reason for the creation of ceramic-matrix composites.
24. Briefly describe the mechanism of transformation toughening.
25. For carbon-carbon composites, briefly discuss
(a) the processing technique employed,
(b) their desirable properties, and
(c) principal applications.
26. (a) Define hybrid composite.
(b) Cite the principal advantage for using this type of composite.
27. (a) Briefly describe each of the three fiber-reinforced processing
techniques discussed in this chapter.
(b) Discuss principal advantages for the employment of each technique.
28. Name and briefly describe the two subclassifications of structural
composites.
29. Cite the principal advantage of using a structural laminate.
30. Name the two components of sandwich panels, and at least one function
that each component serves.
31. Briefly describe the construction of a honeycomb structure.
43
CHAPTER 17
CORROSION AND DEGRADATION OF MATERIALS
LEARNING OBJECTIVES
1. Define corrosion.
2. (a) Distinguish between oxidation and reduction reactions.
(b) State which reaction occurs at the anode and which at the cathode.
3. List five possible reduction reactions that can occur in aqueous solutions.
4. Given an oxidation reaction and a reduction reaction specify the overall
electrochemical reaction.
5. Describe the following:
(a) galvanic couple,
(b) standard half-cell, and
(c) standard hydrogen electrode.
6. For two pure metals that are electrically connected and submerged in
solutions of their respective ions, given the molar concentrations of these
solutions, the standard emf series, and temperature,
(a) compute the cell potential, and
(b) write the spontaneous direction for the electrochemical reaction.
7. (a) Describe the galvanic series, (b) the conditions under which it was
generated, and (c) its utility.
8. Given the weight loss over some time period for a piece of metal of specified
density and area, compute the corrosion penetration rate in both mils per
year and millimeters per year.
9. For some metal oxidation reaction, given the current density, determine the
oxidation rate in units of moles per meters squared per second.
10W. Define (a) polarization, and (b) overvoltage.
11W. (a) Name and briefly describe the two different types of polarization.
(b) Specify the conditions under which each type is rate controlling.
(c) Make a plot of overvoltage versus the logarithm of current density for both
types of polarization.
12W. Define exchange current density.
44
13W. For some electrochemical reaction the rate of which is controlled by
activation polarization, determine
(a) the rate of oxidation, and
(b) the value of the corrosion potential, given appropriate activation
polarization data for both oxidation and reduction half-reactions.
14. Define passivity.
15W. (a) For a metal that exhibits passive behavior, make a schematic
polarization plot of electrochemical potential versus the logarithm of
current density.
(b) Using such a plot demonstrate how a metal may display both active and
passive corrosion behaviors.
16. (a) List four environmental factors that can influence corrosion.
(b) Describe how each of these factors normally affects the corrosion rate.
17. For each of the eight forms of corrosion, and, in addition, hydrogen
embrittlement, do the following:
(a) Describe the nature of the corrosion process;
(b) With all but uniform corrosion, cite the corrosion mechanism; and
(c) Note at least one measure that may be taken to reduce or eliminate the
likelihood of corrosion.
18. In addition to cathodic protection, list four general measures that are
commonly used to prevent corrosion.
19. (a) Describe the mechanism of cathodic protection.
(b) Describe each of the three cathodic protection techniques.
20. Briefly describe the mechanism by which an oxide layer forms on the
surface of a metal.
21. (a) Given the atomic weight of a metal and the molecular weight of its
oxide, as well as values for their densities, compute the Pilling-Bedworth
ratio.
(b) On the basis of this ratio, predict whether or not the oxide coating will act
as a protective barrier for the metal.
22. (a) Write the equation for weight gain per unit area as a function of time for
each of linear, parabolic, and logarithmic oxidation rates.
(b) Given weight gain-time data for the oxidation of some metal or alloy,
determine whether the kinetics are linear, parabolic, or logarithmic.
45
23. Explain why ceramic materials are, in general, very resistant to corrosion.
24. Discuss two degradation processes observed in polymers that are exposed
to liquid solvents.
25. For polymeric materials, discuss the causes and consequences of
molecular chain bond rupture.
26. Make a schematic diagram showing the anatomy of the human hip.
27. List and briefly explain six biocompatibility considerations relative to the
employment of artificial hip replacements.
28. Name the four components found in the artificial hip replacement, and, for
each, list its specific material requirements.
46
CHAPTER 18
ELECTRICAL PROPERTIES
LEARNING OBJECTIVES
1. Give two equation forms of Ohm's law.
2. Given the electrical resistance, as well as length and cross-sectional area of
a specimen, compute its resistivity and conductivity.
3. Compute the electric field intensity given the voltage drop across a specified
distance.
4. Make the distinction between electronic and ionic conduction.
5. Describe the formation of electron energy bands as a large number of atoms,
initially widely separated and isolated from one another, are gradually
brought together, and allowed to bond to one another such that a
crystalline solid is formed.
6. Briefly describe the four possible electron band structures for solid materials.
7. Briefly describe electron excitation events in metals, semiconductors, and
insulators by which free electrons are produced, which electrons may
participate in the electronic conduction process.
8. Calculate the mobility of an electron, given its drift velocity and the
magnitude of the electric field.
9. Calculate the electrical conductivity of a metal, given the number of free
electrons per unit volume, the electron mobility, and the electrical charge
on an electron.
10. (a) Cite three types of electron scattering centers for metals.
(b) Write Matthiessen's rule in equation form.
11. Calculate the temperature component of electrical resistivity for a metal atsome temperature, given values for its ρo and a constants.
12. For a solid solution alloy, given the impurity concentration (in atom fraction)
and a value for the constant A, calculate the impurity contribution to the
electrical resistivity.
47
13. For a two-phase metal alloy, determine the impurity contribution to the
electrical resistivity given volume fractions and electrical conductivity
values for the two phases.
14. Distinguish between intrinsic and extrinsic semiconducting materials.
15. Cite two examples for each of the Groups IVA, IIIA-VA, and IIB-VIAsemiconducting materials.
16. Describe the formation of a hole in terms of electron excitations in
semiconductors.
17. Compute the electrical conductivity of an intrinsic semiconductor given the
electron and hole mobilities, the electronic charge, and either the number
of electrons or number of holes per unit volume.
18. For n-type extrinsic semiconduction:
(a) Describe the excitation of a donor electron in terms of both electron
bonding and energy band models.
(b) Compute the electrical conductivity given the electron mobility, the
number of free electrons per unit volume, and the electronic charge.
19. For p-type extrinsic semiconduction:
(a) Describe the electron excitation that involves the formation of a hole in
terms of both electron bonding and energy band models.
(b) Compute the electrical conductivity given the hole mobility, the number of
holes per unit volume, and the electronic charge.
20. (a) On a plot of logarithm of carrier (electron, hole) concentration versus
absolute temperature draw schematic curves for both intrinsic and extrinsic
materials.
(b) On the extrinsic curve note freeze-out, extrinsic, and intrinsic regions.
21. On a plot of logarithm of carrier mobility versus logarithm of impurity
concentration plot schematic curves for both electron and hole mobilities.
22. Given a plot of logarithm electron/hole mobility versus logarithm of
temperature (with curves at various dopant levels), compute the
conductivity of a semiconductor at specified dopant type and dopant
concentration level and specified temperature.
23W. (a) Briefly describe the experimental setup that is used to demonstrate
the Hall effect.
(b) Note the primary reason that Hall effect measurements are made.
48
24W. Compute the Hall constant, given the specimen thickness, and values for
the electric current, applied magnetic field, and the Hall voltage.
25. (a) For a p-n rectifying junction describe electron and hole distributions for
both forward and reverse biases.
(b) Now explain the process of rectification by means of electron and hole
motions in response to these two bias modes.
26. In terms of current-voltage characteristics for both forward and reverse
biases, describe how a p-n junction acts as a rectifier.
27. For both junction and MOSFET transistors:
(a) detail the configuration of the various components, and
(b) explain the operation of both transistor types.
28. Compute the mobility of an ionic species given its valence and its diffusion
coefficient, and, in addition, temperature, Boltzmann's constant, and the
electrical charge associated with an electron.
29. Compare electrical conductivity magnitudes for typical ceramics and
polymers with those of the metallic materials.
30W. Define the following: (a) electric dipole, (b) dielectric material, and (c)
polarization.
31W. Compute capacitance given the applied voltage and magnitude of charge
stored on each plate.
32W. Given plate area and plate separation for a parallel-plate capacitor, and,
in addition, the permittivity of a vacuum, calculate the capacitance.
33W. Compute the dielectric constant for some material given its permittivity, as
well as the permittivity of a vacuum.
34W. Calculate the dipole moment for a single dipole given the magnitude of
each dipole charge and the charge separation distance.
35W. Given the electric field and the permittivity for a material, determine the
dielectric displacement.
36W. Briefly explain how the charge storing capacity of a capacitor may be
increased by the insertion and polarization of a dielectric material between
its plates.
37W. Compute the polarization for a typical dielectric material given its
permittivity, as well as the permittivity of a vacuum and the applied electric
field.
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38W. Name and describe the three types of polarization.
39W. Define and explain relaxation frequency as it applies to dielectric
materials.
40W. Define (a) dielectric breakdown, and (b) dielectric strength.
41. (a) Briefly describe the phenomenon of ferroelectricity.
(b) Explain ferroelectric behavior in barium titanate.
42. Briefly describe the piezoelectric phenomenon.
43W. List five functions that an integrated circuit package must perform.
44W. Describe the components and their functions for a leadframe.
45W. (a) Name and briefly describe the three processes that are carried out
during integrated circuit packaging.
(b) Cite at least two materials that are employed in each of these processes.
46W. Briefly describe the tape automated bonding process.
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CHAPTER 19
THERMAL PROPERTIES
LEARNING OBJECTIVES
1. Define heat capacity and specific heat.
2. Note the primary means by which thermal energy is assimilated by solid
materials.
3. Define phonon.
4. Cite the equation for the low-temperature temperature dependence of heat
capacity at constant volume.
5. Define Debye temperature.
6. At temperatures in excess of the Debye temperature, cite the approximate
value for the constant volume heat capacity.
7. Determine the linear coefficient of thermal expansion, given the initial
specimen length, as well as the length alteration which accompanies a
specified temperature change.
8. For an isotropic material, estimate the volume coefficient of thermal
expansion from the linear value.
9. Briefly explain the phenomenon of thermal expansion from an atomic
perspective using a plot of potential energy versus interatomic separation.
10. Make a qualitative comparison of the coefficients of thermal expansion for
metals, ceramics, and polymers.
11. Define thermal conductivity.
12. (a) Note the two mechanisms of heat conduction.
(b) Compare the relative magnitudes of these contributions in each of metals,
ceramics, and polymeric materials.
13. (a) Determine the Wiedemann-Franz constant for a material at some
specified temperature, given values for its thermal and electrical
conductivities at this temperature.
(b) Briefly explain why values of this constant are virtually the same and
independent of temperature for all metallic materials.
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14. For an isotropic solid material which ends are restrained by rigid supports,
calculate the thermal stress that results from a specified temperature
change, given values of the elastic modulus and coefficient of thermal
expansion.
15. Explain the establishment of thermal stresses as a body of material is
heated or cooled.
16. Estimate the thermal shock parameter for a material given its fracture
strength, thermal conductivity, modulus of elasticity, and linear coefficient
of thermal expansion.
17W. (a) Name the three components of the Thermal Protection System for the
Space Shuttle Orbiter.
(b) Cite the in-service temperature range for each of these components.
18W. Describe the composition, microstructure, and general properties of the
ceramic tiles that are used on the Space Shuttle Orbiter.
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CHAPTER 20
MAGNETIC PROPERTIES
LEARNING OBJECTIVES
1. Describe a magnetic dipole.
2. Calculate the magnetic field strength within a coil of wire given the number of
wire turns, the length of the coil, and the magnitude of the current.
3. Determine the magnetic flux density for a specified field strength
(a) in a vacuum given the permeability of a vacuum, and
(b) within some solid material given its permeability.
4. Compute the relative permeability for some material given its permeability,
and the permeability of a vacuum.
5. Calculate the magnetic susceptibility of some material given the value of its
relative permeability.
6. Determine the magnetization of some material given the magnitude of the
applied magnetic field strength and, in addition, its magnetic susceptibility.
7. From an electronic perspective, note and briefly explain the two sources for
magnetic moments in materials.
8. For a specific electron, given its spin orientation as well as its magnetic
quantum number, and, in addition, the magnitude of the Bohr magneton,
compute orbital and spin contributions to its overall magnetic moment.
9. Briefly explain why some atoms will possess no net magnetic moment.
10. (a) Briefly explain the nature and source of diamagnetism.
(b) Note the order-of-magnitude value for the volume susceptibility of
diamagnetic materials.
11. (a) Briefly explain the nature and source of paramagnetism.
(b) Note the order-of-magnitude value range for the volume susceptibility of
paramagnetic materials.
12. (a) Briefly explain the nature and source of ferromagnetism.
(b) For a ferromagnetic material, compute the maximum saturation
magnetization, given the number of Bohr magnetons per atom, the value of
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the Bohr magneton, Avogadro's number, and the density and atomic
weight of the material.
13. Briefly explain the nature and source of antiferromagnetism.
14. (a) In terms of the crystal structure of cubic ferrites, explain the source of
ferrimagnetism.
(b) Calculate the saturation magnetism for a cubic ferrite given its
composition, the number of Bohr magnetons associated with each cation
type, the value of the Bohr magneton, and the unit cell edge length.
15. (a) Define Curie temperature.
(b) Briefly explain why saturation magnetization diminishes with increasing
temperature for ferromagnetic and ferrimagnetic materials.
16. Describe the natures of (a) a domain, and (b) a domain wall.
17. (a) Describe magnetic hysteresis.
(b) Explain why ferromagnetic and ferrimagnetic materials experience
magnetic hysteresis.
(c) In terms of magnetic hysteresis, explain why these materials may be
permanent magnets.
18. Given the complete hysteresis loop for a ferromagnetic or ferrimagnetic
material, determine:
(a) the initial permeability,
(b) the remanence, and
(c) the coercivity.
19. (a) Define soft magnetic material.
(b) Cite the characteristics that are required in order for a ferromagnetic or
ferrimagnetic material to be magnetically soft.
20. (a) Define hard magnetic material.
(b) Cite the characteristics that are required in order for a ferromagnetic or
ferrimagnetic material to be magnetically hard.
21. Briefly explain how information is stored on and retrieved from a magnetic
medium using a recording head.
22. (a) Describe the characteristics of particulate and thin film magnetic
storage media.
(b) For each medium type, briefly explain the mechanism of magnetic
storage.
54
23. Describe the superconductivity phenomenon.
24. Define the superconductive (a) critical temperature, (b) critical magnetic
field, and (c) critical current density.
25. In terms of magnetic response, describe the characteristics of types I and
II superconductors.
26. Briefly describe the Meissner effect.
55
CHAPTER 21
OPTICAL PROPERTIES
LEARNING OBJECTIVES
1. Cite the wavelength range for visible light radiation.
2. Note the relationship between the velocity of electromagnetic radiation in a
vacuum, and vacuum values of the electric permittivity and magnetic
permeability.
3. Given the velocity of electromagnetic radiation in a vacuum as well as the
radiation frequency, compute the radiation wavelength.
4. Define photon.
5. Compute the energy of a photon given its frequency and the value of
Planck's constant.
6. List the three phenomena that may occur with light radiation as it passes
from one medium into another.
7. Cite distinctions between optical transparency, translucency, and opacity.
8. (a) Briefly describe electronic polarization that results from electromagnetic
radiation-atomic interactions.
(b) Cite two consequences of electronic polarization.
9. Briefly explain how electromagnetic radiation may be absorbed by electron
transitions.
10. Briefly explain why metallic materials are opaque to visible light.
11. Note what determines the color of metallic materials.
12. Define index of refraction.
13. Calculate the index of refraction for a material given values of its dielectric
constant and relative magnetic permeability.
14. Note the influence of atomic/ionic size on index of refraction.
15. Calculate the reflectivity at an interface for normally incident light given the
indexes of refraction for the media on both sides of the interface.
16. For high-purity insulators and semiconductors:
(a) describe the mechanism of photon absorption;
56
(b) explain how the magnitude of the band gap energy influences photon
absorption;
(c) cite band gap energy values for which there is no absorption of visible
light radiation; and
(d) cite band gap energy values for which there is only partial absorption of
visible light radiation.
17. For insulators and semiconductors that contain electrically active defects:
(a) describe the mechanism of photon absorption;
(b) cite two decay paths that are possible as excited electrons return to their
ground states.
18. Calculate the intensity of nonabsorbed radiation that passes through a
transparent medium of specified thickness, given the intensity of
nonreflected radiation incident on the front face, as well as the absorption
coefficient for the particular medium.
19. Determine the intensity of radiation that emerges from the back face of a
transparent solid of specified thickness, give the intensity of radiation that
impinges on the front face, and, in addition, values of the material's
reflectance and absorption coefficient.
20. (a) Briefly explain why some semiconducting materials appear colored.
(b) Now explain the source of color in many insulating materials.
21. (a) For inherently transparent dielectric materials, note three sources of
internal scattering that can lead to translucency and opacity.
(b) Briefly explain why internal scattering occurs for each of these sources.
22. Briefly explain why amorphous materials are normally transparent.
23. (a) Describe the phenomena of luminescence and electroluminescence.
(b) Distinguish between fluorescence and phosphorescence.
24. Briefly describe the phenomenon of photoconductivity.
25. Briefly describe the construction of and operation of (a) the ruby laser, and
(b) the semiconductor laser.
26. List and describe the functions of various components for an optical fiber
communications system.
27. Explain the transmission of digitized signals through optical fibers.
28. Note and briefly explain functions of the several components that are
found in an optical fiber.
57
29. Explain what precautions are taken to minimize scattering and attenuation
of a light beam that passes through an optical fiber.
58
CHAPTER 22W
ECONOMIC, ENVIRONMENTAL, AND SOCIETAL ISSUESIN MATERIALS SCIENCE AND ENGINEERING
LEARNING OBJECTIVES
1W. (a) List three factors over which an engineer has control that affect the cost
of a product.
(b) Briefly discuss each of these factors.
2W. (a) Diagram the total materials cycle.
(b) Briefly discuss relevant issues that pertain to each stage of this cycle.
3W. List the two inputs and five outputs for the life cycle analysis/assessment
scheme.
4W. Cite relevant issues for the "green design" philosophy of product design.
5W. Discuss recyclability/disposability issues relative to (a) metals, (b) glass, (c)
plastics and rubber, and (d) composite materials.
