1.1. Explain the difference between a unit cell and a single crystal.
1.2. In tables on crystal structures, iron is listed as having both a bcc and an fcc
structure. Why?
1.3. Define anisotropy. What is its significance?
1.4. What effects does recrystallization have on the properties of metals?
1.5. What is strain hardening, and what effects does it have on the properties of
metals?
1.6. Explain what is meant by structure-sensitive and structure-insensitive properties
of metals.
1.7. Make a list of each of the major kinds of imperfection in the crystal structure of
metals, and describe them.
1.8. What influence does grain size have on the mechanical properties of metals?
1.9. What is the relationship between the nucleation rate and the number of grains per
unit volume of a metal?
2.l. Distinguish between engineering stress and true stress.
2.2. Describe the events that occur when a specimen undergoes a tension test. Sketch
a plausible stress-strain curve, and identify all significant regions and poin
between them. Assume that loading continues up to fracture.
2.3. What is ductility, and how is it measured?
2.4. In the equation 0' = Ke", which represents the stress-strain curve for a material,
what is the significance of the exponent n?
2.5. What is strain-rate sensitivity, and how is it measured?
2.6. What test can measure the properties of a material undergoing shear strain?
2.7. What testing procedures can be used to measure the properties of brittle materials,
such as ceramics and carbides?
2.8. Describe the differences between brittle and ductile fracture.
2.9. Differentiate between stress relaxation and creep.
2.10. Explain what uniform elongation means in tension testing.
2.11. Describe the difference between deformation rate and strain rate. What unit does
each one have?
2.l2. Describe the difficulties involved in making a compression test.
2.l3. What is Hooke’s law? Young’s modulus? Poisson’s ratio?
2.l4. Describe the difference between transgranular and intergranular fracture.
2.15. What is the reason that yield strength is generally defined as a 0.2% offset
strength?
2.l6. Why does the fatigue strength of a specimen or part depend on its surface finish?
2.17. If striations are observed under microscopic examination of a fracture surface,
what do they suggest regarding the mode of fracture?
3.I. Describe the difference between a solute and a solvent.
3.2. What is a solid solution?
3.3. What are the conditions for obtaining (a) substitutional and (bl interstitial solid
solutions?
3.4. Describe the difference between a single-phase and a two-phase system.
3.5. Explain what is meant by “second-phase particle.”
3.6. Describe the major features of a phase diagram.
3.7. What do the terms “equilibrium” and “constitutional,” as applied to phase
diagrams, indicate?
3.8. What is the difference between “eutectic” and“eutectoid”?
3.9. What is tempering? Why is it performed?
3.10. Explain what is meant by “severity of quenching.”
3.l1. What are precipitates? Why are they significant in precipitation hardening?
3.12. What is the difference between natural and artificial aging?
3.l3. Describe the characteristics of ferrite, austenite, and cementite.
3.l4. What is the purpose of annealing?
4.l. What are the major categories of ferrous alloys?
4.2. List the basic raw materials used in making iron and steel, and explain their
functions.
4.3. List the types of furnaces commonly used in steelmaking, and describe their
characteristics.
4.4. List and explain the characteristics of the types of steel ingots.
4.5. What does rejqning mean? How is it done?
4.6. What advantages does continuous casting have over casting into ingots?
4.7. Name the four alloying elements that have the greatest effect on the properties of
steels.
4.8. What are trace elements?
4.9. What are the percentage carbon contents of lowcarbon, medium-carbon, and
high-carbon steels?
4.10. How do stainless steels become stainless?
4.l1. What are the major alloying elements in tool and die steels and in high-speed
steels?
4.12. How does chromium affect the surface characteristics of stainless steels?
4.13. What kinds of furnaces are used to refine steels?
4.14. What is high-speed steel?
4.15. What are the applications of advanced high-strength steels?
5.l. Given the abundance of aluminum in the earth’s crust, explain why it is more
expensive than steel.
5.2. Why is magnesium often used as a structural material in power hand tools? Why
are its alloys used instead of pure magnesium?
5.3. What are the major uses of copper? What are the alloying elements in brass and
bronze, respectively?
5.4. What are superalloys? Why are they so named?
5.5. What properties of titanium make it attractive for use in race-car and jet-engine
components? Why is titanium not used widely for engine components in
passenger cars?
5.6. Which properties of each of the major refractory metals define their most useful
applications?
5.7. What are metallic glasses? Why is the word “glass”
5.8. What is the composition of (a) babbitts, (b) pewter, and (C) sterling silver?
5.9. Name the materials described in this chapter that have the highest (a) density, (b)
electrical conductivity, (c) thermal conductivity, (d) strength, and (e) cost.
5.10. Describe the advantages to using zinc as a coating for steel.
5.l1. What are nanomaterials? Why are they being developed?
5.12. Why are aircraft fuselages made of aluminum alloys, even though magnesium is
the lightest metal?
6.1. Describe the differences between expendable and permanent molds.
6.2. Name the important factors in selecting sand for molds.
6.3. What are the major types of sand molds? What are their characteristics?
6.4. List important considerations when selecting pattern materials.
6.5. What is the function of a core?
6.6. What is the difference between sand-mold and shell mold casting?
6.7. What are composite molds? Why are they used?
6.8. Describe the features of plaster-mold casting.
6.9. Name the type of materials typically used for permanent-mold casting processes.
6.10. What are the advantages of pressure casting over other processes?
6.11. List the advantages and limitations of die casting.
6.12. What is the purpose of a riser? A vent?
6.13. What is squeeze casting? What are its advantages?
6.14. What are the advantages of the lost-foam casting process?
7.1. Why are steels more difficult to cast than cast irons?
7.2. What is the significance of hot spots in metal casting?
7.3 What is shrinkage allowance? Machining allowance?
7.4. Explain the reason for drafts in molds.
7.5 What are light castings and where are they used most commonly?
7.6. Name the types of cast irons generally available, and list their major
characteristics and applications.
7.7. Comment on your observations regarding Fig. 12.4.
7.8. Describe the difference between a runner and a gate.
7.9. What is the difference between machining allowance and dimensional tolerance?
8.l. What is the difference between cold, warm, and hot forging?
8.2. Explain the difference between open-die and impression-die forging.
8.3. Explain the difference between fullering, edging, and blocking.
8.4. What is flash? What is its function?
8.5. Why is the intermediate shape of a part important in forging operations?
8.6. Describe the features of a typical forging die.
8.7. Explain what is meant by “load limited,” “energy limited,” and “stroke limited”
as these terms pertain to forging machines.
8.8. What type of parts can be produced by rotary swaging?
8.9. Why is hubbing an attractive alternative to producing simple dies?
8.l0. What is the difference between piercing and punching?
9.1. Explain what is meant by solid-state welding.
9.2. What is cold welding? Why is it so called?
9.3. What is (a) a ferrule, (b) filled gold, and (C) a flyer plate?
9.4. What are faying surfaces in solid-state welding processes?
9.5. What is the basic principle of (a) ultrasonic welding and (b) diffusion bonding?
9.6. Describe the advantages and limitations of explosion welding.
9.7. Describe the principle of resistance-welding processes.
9.8. What type of products are suitable for stud welding? Why?
9.9. Describe how high-frequency butt welding operates.
10.l. What is the difference between brazing and braze welding?
10.2. Are fluxes necessary in brazing? If so, why?
10.3. Why is surface preparation important in adhesive bonding?
10.4. Soldering is generally applied to thinner components. Explain Why.
10.5. Explain the reasons that a variety of mechanical joining methods have been
developed over the years.
10.6. Describe the similarities and differences between the functions of a bolt and
those of a rivet.
10.7. What precautions should be taken in the mechanical joining of dissimilar
metals?
10.8. What difficulties are involved in joining plastics? Why?
10.9. What are the principles of (a) wave soldering and (b) reflow soldering?
10.l0. What is a peel test? Why is it useful?
1l.l. Explain why continuous chips are not necessarily desirable.
11.2. Name the factors that contribute to the formation of discontinuous chips.
11.3. Explain the difference between positive and negative rake angles. What is the
importance of the rake angle?
11.4. Comment on the role and importance of the relief angle.
11.5. Explain the difference between discontinuous chips and segmented chips.
11.6. Why should we be interested in the magnitude of the thrust force in cutting?
11.7. What are the differences between orthogonal and oblique cutting?
11.8. Is there any advantage to having a built~up edge on a tool? Explain.
11.9. What is the function of chip breakers? How do they function?
11.10. Identify the forces involved in a cutting operation. Which of these forces
contributes to the power required?
11.11. Explain the characteristics of different types of tool wear.
11.l2. List the factors that contribute to poor surface finish in cutting.
11.13. Explain what is meant by the term mac/ainability and what it involves. Why
does titanium have poor machinability?
12.l. Explain Why milling is such a versatile machining operation.
12.2. Describe the different types of cutters used in milling operations and give an
application of each type.
12.3. Explain the relative characteristics of climb milling and up milling.
12.4. Describe the geometric features of a broach and explain their functions.
12.5. Why is sawing a commonly used process? Why do some saw blades have
staggered teeth? Explain.
12.6. What advantages do bed-type milling machines have over
column-and-knee-type machines for production operations?
12.7. Explain why the axis of a hob is tilted with respect to the axis of the gear blank.
12.8. What is a shell mill? Why is it used?
12.9. Why is it difficult to saw thin sheet metals?