Materials

Front 1

What is the dominant type of binding for Titanium?

ionic
hydrogen
covalent
van der waals
metallic

Back 1

Metallic

Front 2

Which of the following materials may form crystalline solids?
A. Polymers
B. Metals and Ceramics
C. All of the above
D. None of the above

Back 2

C. All of the above

Front 3

For the face-centered cubic crystal structure: How many atoms are associated with each unit cell?
A. 1
B. 2
C. 4
D. 14

Back 3

C. 4

Front 4

6. For the face-centered cubic crystal structure, what is the coordination number?
A. 4
B. 6
C. 8
D. 12

Back 4

D. 12

Front 5

7. For the face-centered cubic crystal structure what is the atomic packing factor?
A. 0.50
B. 0.68
C. 0.74
D. 0.80

Back 5

C. 0.74

Front 6

13. The atomic diameter radius of a BCC crystal (if a is lattice parameter) is (a) a/(√3/4)
(b) a/2
(c) a/(4/√3)
(d) a/(4/√2)

Back 6

(c) a/(4/√3)

Front 7

14. Miller indices of close packed planes in a bcc crystal (a) (100)
(b) (110)
(c) (111)
(d) depends on the atom type (e.g. Fe or Al)

Back 7

(b) (110)

Front 8

15. The plane (1͞11) is parallel to
(a) ( ͞11͞1)
(b) ( ͞1͞11) (c) (111) (d) (1͞11)

Back 8

(a) ( ͞11͞1)

Front 9

16. If I quench a solid metal from high temperature (e.g. 0.8 Tmp) the number of vacancies will be ___________ if I cool slowly.
A. less than
B. greater than
C. the same as

Back 9

B. greater then

Front 10

7. Calculate the fraction of atom sites that are vacant for silver at 661°C. (Silver has an fcc crystal structure) Assume an energy for vacancy formation of 0.63 eV/atom.

a) 4.0 x 10-4 b) 1.58 x 10-5 c) 1.6 x 10-3 d)6.664 x 10-28

Back 10

a) 4.0 x 10-4

Front 11

18. The surface energy of a single crystal depends on the crystallographic orientation with respect to the
surface.
a) always true
b) always false
c) it depends on the materials

Back 11

a) always true

Front 12

Which is not a 2-dimensional imperfection?
(a) Twin boundary
(b) Dislocation
(c) Surface
(d) Grain boundary

Back 12

(b) Dislocation

Front 13

Which are thermodynamically stable defects?
(a) Point defects
(b) Line defects
(c) Surface defects
(d) Volume defects

Back 13

(a) Point defects

Front 14

Which of the following is false?
(a) Line defects are thermodynamically stable
(b) Dislocation can end inside a crystal without forming loop (c) ABC ABC ABC...is stacking sequence for HCP crystal (d) All
(e) None

Back 14

all

Front 15

Modulus of elasticity ________________ as the bond energy increases
(a) increases
(b) decreases
(c) does not change

Back 15

increases

Front 16

The diffusion rate for an interstitial atom is ________________ that of a substitutional atom.
(a) greater than
(b) less than
(c) the same as

Back 16

greater than

Front 17

Solid solubility of element A in element B __________________ as the difference in their atomic radii decreases.
(a) increases (b) decreases (c) does not change

Back 17

increases

Front 18

The stress required for slip in the (100) is ________________ what is required in the (110) in bcc metals.
(a) greater than (b) less than (c) same as

Back 18

greater than

Front 19

With increasing bond strength the melting temperature will ___________________.
(a) increase (b) decrease (c) not change

Back 19

increase

Front 20

Atoms in the slip plane are _________________ distance apart as atoms in other planes.
(a) closer (b) further (c) the same

Back 20

closer

Front 21

In general hcp metals will exhibit ____________ ductility than fcc metals
(a) more (b) less (c) roughly the same

Back 21

less

Front 22

After an edge dislocation has passed through some region of a crystal, the atomic arrangement of that
region is _______________
a) disordered b) the same as before (ordered) c) amorphous

Back 22

same as before

Front 23

For a particular crystal structure, the slip direction is that direction in the slip plane having the: a) highest linear density b) lowest linear density c) it is unrelated to linear density

Back 23

highest linear density

Front 24

For a particular crystal structure, the slip plane is that plane having the:
a) least dense atomic packing b) densest atomic packing c) it is unrelated to packing density

Back 24

densest atomic packing

Front 25

Niobium has an atomic radius of 0.143 nm and is bcc. Its atomic weight is 92.91 Calculate its density
a. 4.29 g/cm3
b. 8.57 g/cm3
c. 543.7 g/cm3 d. 105.56 g/cm3

Back 25

b. 8.57 g/cm3

Front 26

If the lattice of a material expands (e.g. due to substitution of larger atoms of a different type) the peaks on the diffraction pattern will
a) move to the left (smaller 2θ) b) move to the right (larger 2θ) c) remain unchanged (no shift)

Back 26

a) move to the left (smaller 2θ)

Front 27

A hypoeutectoid composition steel will have an amount of ferrite in its microstructure that is
_______________ that found in a eutectoid steel.
(a) greater than (b) less than (c) the same as

Back 27

greater than

Front 28

The hardness of tempered martensite is _____________ that of untempered martensite. (a) greater than (b) less than (c) the same as

Back 28

less than

Front 29

The sintering rate of a ceramic material will ____________________ as the particle size is reduced. (a) increase (b) decrease (c) not change

Back 29

increase

Front 30

The melting point of a polymer will ______________ as the degree of polymerization decreases. (a) increase (b) decrease (c) not change

Back 30

decrease

Front 31

The eutectoid composition of steel _______________________ as more carbon is added to the system. (a) increase (b) decrease (c) not change

Back 31

not change

Front 32

The modulus of elasticity of polyethylene will ____________________ as the strain rate is increased. (a) increase (b) decrease (c) not change

Back 32

increase

Front 33

The degree of crystallization of polyethylene will ____________________ as the cooling rate from high temperature is decreased.
(a) increase (b) decrease (c) not change

Back 33

increase

Front 34

The eutectoid composition of an alloy will ____________________ with cold working.
(a) increase (b) decrease (c) not change

Back 34

not change

Front 35

Adding sulfur to polyisoprene (rubber) causes its modulus of elasticity to _____________.
(a) increase (b) decrease (c) not change

Back 35

increase

Front 36

If the austenite grain size increases, the hardenability of a steel alloy will _________________? (a) increase (b) decrease (c) not change

Back 36

increase

Front 37

For each of the following pairs of polymers decide which is more likely to crystallize?

a) linear and syndiotactic polyvinyl chloride; b) linear and isotactic polystyrene

Back 37

a) linear and syndiotactic polyvinyl chloride

Front 38

For each of the following pairs of polymers decide which is more likely to crystallize?

a) linear and syndiotactic polypropylene; b) crosslinked cis-isoprene

Back 38

a) linear and syndiotactic polypropylene

Front 39

For each of the following pairs of polymers decide which is more likely to crystallize?

a) network phenol-formaldehyde; b) linear and isotactic polypropylene

Back 39

b) linear and isotactic polypropylene

Front 40

For each of the following pairs of polymers decide which is more likely to crystallize?

a) lightly branched isotactic polypropylene; b) linear polyethylene

Back 40

b) linear polyethylene

Front 41

For each of the following pairs of polymers decide which is more likely to crystallize?

a) alternating poly(styrene-ethylene) copolymer; b) random poly(vinyl chloride-tetrafluoroethylene) copolymer

Back 41

a) alternating poly(styrene-ethylene) copolymer

Front 42

For each of the following pairs of polymers, decide which is more likely to have the greater tensile strength?

a) lightly cross-linked polyethylene; b) network phenol-formaldehyde

Back 42

b) network phenol-formaldehyde

Front 43

For each of the following pairs of polymers, decide which is more likely to have the greater tensile strength?

a) lightly cross-linked polyvinyl chloride; b)branched polyvinyl chloride

Back 43

a) lightly cross-linked polyvinyl chloride

Front 44

For each of the following pairs of polymers, decide which is more likely to have the greater tensile strength?

a) 95% crystalline and linear PTFE having a number average molecular weight of 650,000 g/mol;
b)80% crystalline and linear PTFE having a number average weight of 500,000 g/mol

Back 44

a) 95% crystalline and linear PTFE having a number average molecular weight of 650,000 g/mol

Front 45

For each of the following pairs of polymers, decide which is more likely to have the greater tensile strength?

a) Atactic polypropylene having a weight average molecular weight of 750,000 g/mol
b)isotactic polypropylene having a weight average molecular weight of 750,000 g/mol

Back 45

b)isotactic polypropylene having a weight average molecular weight of 750,000 g/mol

Front 46

For each of the following pairs of polymers, decide which is more likely to have the greater tensile strength?

a) alternating styrene butadience co-polymer; b)graft styrene butadiene co-polymer

Back 46

a) alternating styrene butadience co-polymer

Front 47

Polyethylene is being processed. H2O2 is used as the source of free radicals. Batch A is made with 0.1 wt. %
H2O2. Batch B is made with 0.2 wt. % H2O2. Which batch do you expect to have better mechanical properties?
a) Batch A b) Batch B c) They will be about the same d) there is not enough information to tell

Back 47

Batch A

Front 48

Which alloy has higher hardenability, 1040 or 4340? a) 1040 b) 4340 c) no difference is expected

Back 48

4340

Front 49

How will addition of a filler affect the ease of crystallization of a polymer?
a) it will make it easier b) it will make it more difficult c) it will have no effect

Back 49

b) it will make it more difficult

Front 50

Increasing the carbon content in steel will cause the ductility to __________________.
(a) increase (b) decrease (c) not change

Back 50

b) decrease

Front 51

Increasing the deformation (strain) rate ________________ the toughness of polyethylene.
(a) increases (b) decreases (c) does not change

Back 51

decreases

Front 52

A sample of amorphous polyethylene is found to have an average molecular weight of 25,000 amu. What is the degree of polymerization of the average polyethylene molecule. Assume at. Wt. of C=12, H=1.
a) 2154 b) 1786 c)1250 d) 893

Back 52

d) 893

Front 53

Chemical tempering of a glass leads to increased strength by replacement of near surface ions. The replacement ions _____________________ the ions they substitute for.
a) Are smaller than b) are larger than c) have a higher valence than d) have lower valence than

Back 53

b) are larger than

Front 54

f cupric oxide (CuO) is exposed to a reducing atmosphere at elevated temperatures, some of the Cu2+ ions will become Cu+. What effect will this change in valence have on the stoichiometry?
a) none b) a Frenkel defect will be created c) a Schottky defect wil be created d) the stoichiometry will change (e.g. CuO1-x) to maintain charge balance

Back 54

d) the stoichiometry will change (e.g. CuO1-x) to maintain charge balance

Front 55

Which of the following is false
a) Concrete is made from stone, cement, sand and water b) heat is given off as concrete hardens c) hardening of
concrete can continue for months d) concrete hardens as water evaporates

Back 55

d) concrete hardens as water evaporates

Front 56

A thin piece of glass (~ 2mm) will be ____________________ to temper than a thick (~10mm) piece. a) easier b) more difficult c) equally challenging

Back 56

more difficult

Front 57

A coarse grained polycrystalline material will have a yield strength that is _______________ a fine grained version of the same material.
a) greater than b)less than c) approximately the same as

Back 57

less than

Front 58

Increasing the grain size of a metal ________________ its toughness.
(a) increases (b) decreases (c) does n\not change

Back 58

decreases

Front 59

As the impurity concentration in a dilute solid solution of a metal is decreased, the yield strength _________________.
(a) increases (b) decreases (c) does not change

Back 59

decreases

Front 60

Initially fully annealed Lead ( mp=327C) and Copper (mp=1085C) are both deformed 20% at 50C. Which one experiences the greater change in hardness?
a) lead b) copper c) both will increase the same relative amount d) neither one will change

Back 60

b. copper

Front 61

The area under the stress-strain curve up to fracture is related to:
a) hardness b) ductility c) toughness d) stiffness

Back 61

toughness

Front 62

Bulk diffusion is __________________ grain boundary diffusion
(a) faster than (b) slower than (c) same rate as

Back 62

slower

Front 63

For an alloy of composition 80 wt%Ag cooled slowly from the melt, the mass fraction of proeutectic beta-phase at room temperature is
a) 8% b) 42% c) 50% d) 58%.

Back 63

42%

Front 64

The tendency for brittle fracture _____________ as surface energy decreases. (a) increases (b) decreases (c) does not change

Back 64

increases

Front 65

The diffusion coefficients for copper in aluminum at 500 and 600oC are 4.8 x 10-14 and 5.3 x 10-13 m2/s, respectively. Determine the approximate time (in hrs.) at 500 oC that will produce the same diffusion result (in terms of concentration of Cu at some specific point in the Aluminum) as a 10hr heat treatment at 600oC.
a) 55.2 b) 220.8 c) 1218.8 d) 110.4

Back 65

110.4

Front 66

The driving force for grain growth ______________ as the grain size increases. (a) increases (b) decreases (c) does not change

Back 66

decreases

Front 67

Brittle failure is _____________ likely to occur at low temperatures than(as) at high temperatures. a) less b) more c) just as

Back 67

more

Front 68

With a decrease in strain rate, the yield strength will ___________ . (a) increase (b) decrease (c) not change

Back 68

decrease

Front 69

As the grain size decreases, the hardness ______________ (a) increases (b) decreases (c) is unaffected

Back 69

increases

Front 70

Cold-work causes the resistivity of a metal to ______________. (a) increase (b) decrease (c) not change

Back 70

increase

Front 71

Recrystallization will __________ the yield strength. (a) increase (b) decrease (c) not change

Back 71

decreases

Front 72

As cold work decreases, the density of dislocations __________________. (a) increases (b) decreases (c) is unaffected

Back 72

decreases

Front 73

We are asked to produce a brass wire using an alloy of 70wt%Cu-30wt%Zn with a yield strength of greater than 50 [ksi], and a ductile elongation of more than 20% in the final wire. Is it possible to make such a brass wire?

a) No b) Yes c) There is insufficient information given

Back 73

yes

Front 74

The activation energy for substitutional diffusion is ________________ that for interstitial diffusion .
a) greater than b) less than c) about the same as

Back 74

greater than

Front 75

Shot peening will cause the fatigue strength of an alloy to _______________. (a) decrease (b) increase (c) not change, as it only cleans the surface

Back 75

increases

Front 76

The mobility of dislocations in a metal will ________________ as the ambient temperature is increased. (a) increase (b) decrease (c) not change

Back 76

increases

Front 77

At a given temperature the creep resistance of a strain free single crystal of an alloy will be __________________ that of a heavily cold worked polycrystalline sample of the same alloy.
a) greater than b) less than c) about the same as

Back 77

greater than

Front 78

During recrystallization the number of grains will _____________________.
(a) decrease (b) increase (c) not change

Back 78

increases

Front 79

A cup-and-cone surface is associated with_______________________
a) brittle fracture b) ductile fracture c) case-hardening

Back 79

ductile fracture

Front 80

KIc is a value that quantifies the _________________ of a material.
a) yield strength b) creep resistance c) fracture toughness d) fatigue tendency

Back 80

c) fracture toughness

Front 81

Creep rate will ________________ as the temperature is increased.
(a) increase (b) decrease (c) be relatively unaffected

Back 81

increase

Front 82

Why does aluminum foil have a shiny side and a dull side
a) the top side becomes dull because of oxidation effects
b) only the side contacting the roller is shiny
c) it is too expensive to make both sides shiny
d) temperature uniformity will be improved during cooking e) only one side gets acid-etched

Back 82

b) only the side contacting the roller is shiny

Front 83

For a steel alloy it has been determined that a 12 hr carburizing heat treatment will raise the carbon concentration to 0.38 wt% at a point 1.5 mm from the surface. Estimate the time (in hrs) necessary to achieve the same concentration at a 4.7 mm position for an identical steel and at the same carburizing temperature.
a)118hrs b) 38 hrs c) 451hrs d) 1414hrs

Back 83

118 hours

Front 84

In measuring a stress-strain curve of a metal, I load past the yield stress and release the load. If I then reapply a load, the
yield stress the second time will be __________________ the first value. a) greater than b) less than c) unchanged from

Back 84

greater than

Front 85

An impurity atom that is larger than a host atom for which it substitutes exerts __________ strain on the surrounding crystal lattice.
a) compressive b) tensile c) no

Back 85

compressive

Front 86

Such an atom, in order to cancel some of the strain associated with a dislocation in the lattice (see
figure) will reside __________________ the slip plane a) just above b) just below c) far away from

Back 86

just below

Front 87

What type(s) of bonding would be expected for each of the following materials? For bonds which could share ionic and covalent character, choose the one that would predominate.

a) barium sulfide (BaS)
b) bronze

Back 87

ionic

metallic

Front 88

NaCl has _____ bonding.


CH4 has ____ bonding.

Back 88

ionic

covalent

Front 89

What is the atomic packing factor for the BCC crystal structure?

Back 89

.68

Front 90

For an FCC single crystal, would you expect the surface energy for a (100) plane to be greater or less than that for a (111) plane?

Back 90

greater

Front 91

For a given material, would you expect the surface energy to be greater than, the same as, or less than the grain boundary energy?

Back 91

greater

Front 92

Is the grain boundary energy of a small-angle grain boundary less than for a high-angle one? (yes or no)

Back 92

yes

Front 93

Which of the following characteristics that relate the solutes and solvents (and their atoms) determine the degree to which the solute species dissolves in the solvent?

Valence
Atomic number
Atomic size
Crystal structure
Electronegativity

Back 93

Valence
Atomic size
Crystal structure
Electronegativity

Front 94

Solute or impurity atoms replace or substitute for the host atoms.

Back 94

substitutional

Front 95

Impurity atoms fill the voids or interstices among the host atoms.

Back 95

interstitial

Front 96

Which of the following are linear defects?

A Frenkel defect
A screw dislocation
A Schottky defect
An edge dislocation

Back 96

A screw dislocation
An edge dislocation

Front 97

Diffusion by which mechanism occurs more rapidly in metal alloys?

Back 97

interstitial

Front 98

After an edge dislocation has passed through some region of a crystal, the atomic arrangement of that region is disordered.

Back 98

false

Front 99

The process by which plastic deformation is produced by dislocation motion is called

Back 99

slip

Front 100

During the recovery of a cold-worked material, which of the following statement(s) is (are) true?

Some of the internal strain energy is relieved.
All of the internal strain energy is relieved.
There is some reduction in the number of dislocations.
There is a significant reduction in the number of dislocations, to approximately the number found in the precold-worked state.
The electrical conductivity is recovered to its precold-worked state.
The thermal conductivity is recovered to its precold-worked state.
The metal becomes more ductile, as in its precold-worked state.
Grains with high strains are replaced with new, unstrained grains.

Back 100

Some of the internal strain energy is relieved.
There is some reduction in the number of dislocations.
The electrical conductivity is recovered to its precold-worked state.
The thermal conductivity is recovered to its precold-worked state.

Front 101

During the recrystallization of a cold-worked material, which of the following statement(s) is (are) true?

The electrical conductivity is recovered to its precold-worked state.
Grains with high strains are replaced with new, unstrained grains.
The thermal conductivity is recovered to its precold-worked state.
All of the internal strain energy is relieved.
There is a significant reduction in the number of dislocations, to approximately the number found in the precold-worked state.
The metal becomes more ductile, as in its precold-worked state.
Some of the internal strain energy is relieved.
There is some reduction in the number of dislocations.

Back 101

Grains with high strains are replaced with new, unstrained grains.
All of the internal strain energy is relieved.
There is a significant reduction in the number of dislocations, to approximately the number found in the precold-worked state.
The metal becomes more ductile, as in its precold-worked state.

Front 102

Grain growth must always be preceded by recovery and recrystallization.

Back 102

false

Front 103

How would the plane strain fracture toughness of a metal be expected to change with rising temperature?

Back 103

increase

Front 104

Which of the following factor(s) favor(s) brittle fracture in polymers?

Increasing in temperature.
Increasing in strain rate.
The presence of a sharp notch.
Decreasing specimen thickness.

Back 104

Increasing in strain rate.
The presence of a sharp notch.

Front 105

Which of the following affect(s) the creep characteristics of metals?

Grain size
Ductility
Resilience
Yield strength
Melting temperature
Elastic modulus

Back 105

Grain size
Melting temperature
Elastic modulus

Front 106

If either stress or temperature is increased, indicate which of the following consequences will result.

The instantaneous strain at the time of stress application decreases.
The steady-state creep rate increases.
The rupture lifetime is diminished.

Back 106

The steady-state creep rate increases.
The rupture lifetime is diminished.

Front 107

For the list below, select four metallurgical/processing techniques that are employed to enhance the creep resistance of metal alloys.

anneal the metal alloy
hardening (carburizing, nitriding) or shot peening
polishing the surface to remove stress amplification sites
dispersion strengthening by using an insoluble second phase
solid solution alloying
unidirectional solidification of alloys
increasing the grain size or producing a grain structure with a preferred orientation.

Back 107

dispersion strengthening by using an insoluble second phase
solid solution alloying
unidirectional solidification of alloys
increasing the grain size or producing a grain structure with a preferred orientation.

Front 108

For a solution, which of the following is present in the higher concentration?

solvent
solute

Back 108

solvent

Front 109

At a eutectic point on a binary temperature-composition phase diagram, how many phases are present when the system is at equilibrium?

Back 109

3

Front 110

A eutectoid reaction involves which of the following phases?

One liquid and one solid
One liquid and two solid
Two liquids and one solid
Three solid

Back 110

Three solid

Front 111

Match each transformation description below with the name of a corresponding transformation.

Diffusion-dependent with change(s) in phase composition(s)
Diffusionless
Diffusion-dependent with non change(s) in phase composition(s)

Back 111

eutectoid
martensitic
recrystalization

Front 112

Is the net reduction in ferrite-cementite phase boundary area the driving force for the formation of spheroidite?

Back 112

yes

Front 113

rank by ductile - brittle
Alloy A: 0.20 wt% carbon, coarse pearlite
Alloy B: 0.20 wt% carbon, spheroidite
Alloy C: 0.75 wt% carbon, fine pearlite
Alloy D: 0.75 wt% carbon, coarse pearlite

Back 113

B,A,D,C

Front 114

What is the function of alloying elements (e.g., Cr, V, W, and Mo) in tool steels?

The alloying elements in tool steels improve the capacity of these alloys to be heat treated.

The alloying elements in tool steels combine with the carbon to form easily melted carbide compounds.

The alloying elements in tool steels give rise to a variety of strength-ductility combinations.

The alloying elements in tool steels improve the corrosion resistance.

The alloying elements in tool steels combine with the carbon to form very hard and wear-resistant carbide compounds.

Back 114

The alloying elements in tool steels combine with the carbon to form very hard and wear-resistant carbide compounds.

Front 115

Which type of steel has the designation 4330?

Alloy steel
Plain carbon steel

Back 115

alloy steel

Front 116

Which type of steel has the designation 1015?

Alloy steel
Plain carbon steel

Back 116

plain carbon steel

Front 117

What is the carbon concentration of a steel having the designation 1050?

0.01 wt% C
0.05 wt% C
0.10 wt% C
0.50 wt% C
Impossible to say

Back 117

0.50 wt% C

Front 118

Which three elements in the list below are primary alloying elements for the stainless steels?

Silicon
Copper
Chromium
Vanadium
Molybdenum
Nickel
Tungsten

Back 118

Chromium
Molybdenum
Nickel

Front 119

Which of the sequences below represents the various steels types in order of decreasing hardness?

Medium-carbon > Low-carbon > High-carbon
Low-carbon > High-carbon > Low-carbon
Low-carbon > Medium-carbon > High-carbon
Medium-carbon > High-carbon > Low-carbon
High-carbon > Low-carbon > Medium-carbon
High-carbon > Medium-carbon > Low-carbon

Back 119

High-carbon > Medium-carbon > Low-carbon

Front 120

The successful heat treatment of an alloy steel produces which final phase/microconstituent?

Martensite
Pearlite
Bainite
Tempered martensite
Austenite
Ferrite

Back 120

Tempered martensite

Front 121

Which type of steel contains only residual amounts of alloying elements?

Alloy steel
Plain carbon steel

Back 121

Plain carbon steel

Front 122

Which type of forming operation produces a higher quality surface finish, better mechanical properties, and closer dimensional control of the finished piece?

hot or cold working

Back 122

cold

Front 123

Cold working takes place at a temperature that is below a metal's

Melting temperature
Recrystallization temperature
Eutectoid temperature
Glass transition temperature

Back 123

Recrystallization temperature

Front 124

Which type of forming operation has lower deformation energy requirements?

Cold working
Hot working

Back 124

hot working

Front 125

Forging operations normally take place at

High temperatures
Room temperature
Low temperatures

Back 125

high

Front 126

Hot working takes place at a temperature that is above a metal's

Melting temperature
Recrystallization temperature
Eutectoid temperature
Glass transition temperature

Back 126

Recrystallization temperature

Front 127

What influence does the presence of alloying elements (other than carbon) have on the shape of a hardenability curve?

It causes a much more rapid decrease in hardness with position from the quenched end.
The presence of alloying elements (other than carbon) does not influence on the shape of a hardenability curve.
It causes a much more gradual decrease in hardness with position from the quenched end.

Back 127

It causes a much more gradual decrease in hardness with position from the quenched end.

Front 128

How would you expect a(n) decrease in the austenite grain size to affect the hardenability of a steel alloy?

Increase
Decrease
Has no effect

Back 128

decrease

Front 129

Which of the following may occur during annealing?

Toughness may be increased.
Stresses may be relieved.
A specific microstructure may be produced.
Ductility may be increased.

Back 129

Toughness may be increased.
Stresses may be relieved.
A specific microstructure may be produced.
Ductility may be increased.

Front 130

How does increasing the annealing temperature influence the rate of an annealing process?

Decreases the rate.
Increases the rate.

Back 130

increases

Front 131

How does increasing carbon content influence the hardenability of a steel?

Increases the hardenability.
Decreases the hardenability.

Back 131

increases

Front 132

During a Jominy end-quench test on a plain-carbon steel, the amount of which of the following constituents increases with distance from the quenched end?

Pearlite
Bainite
Austenite
Martensite

Back 132

pearlite

Front 133

Which of the following correctly represents the sequence of procedures that is used to strengthen/harden a precipitation-hardenable alloy?



Quenching; Solution heat treatment; Cold working; Precipitation heat treatment
Cold working; Precipitation heat treatment; Solution heat treatment; Quenching
Precipitation heat treatment; Solution heat treatment; Quenching; Cold working
Solution heat treatment; Quenching; Cold working; Precipitation heat treatment
Cold working; Solution heat treatment; Quenching; Precipitation heat treatment
Solution heat treatment; Quenching; Precipitation heat treatment; Cold working

Back 133

Solution heat treatment; Quenching
Precipitation heat treatment; Solution heat

Front 134

The phase diagram for an alloy system that is amenable to precipitation hardening must display which of the following characteristics?

Have an appreciable maximum solubility of one component in another.
Have a solubility limit that rapidly decreases in concentration of the solute with temperature reduction.
Be for a binary alloy.

Back 134

Have an appreciable maximum solubility of one component in another.
Have a solubility limit that rapidly decreases in concentration of the solute with temperature reduction.

Front 135

An alloy that has been precipitation hardened may be used at elevated temperatures without compromising its hardness and strength.

False
True

Back 135

false

Front 136

The hardening of portland cement is associated with

A chemical reaction involving a compound other than water.
A drying process.
A chemical reaction involving water (i.e. hydration).

Back 136

A chemical reaction involving water (i.e. hydration).

Front 137

What is the distinction between glass transition temperature and melting temperature?

They are two temperatures corresponding to specific viscosity values.
Glass transition temperature is a characteristic of a noncrystalline material and melting temperature is for a crystalline material.
Glass transition temperature is a characteristic of soda-lime glass and melting temperature is for a borosilicate glass.
Melting temperature is a characteristic of a noncrystalline material and glass transition temperature is for a crystalline material.

Back 137

Glass transition temperature is a characteristic of a noncrystalline material and melting temperature is for a crystalline material.

Front 138

Once thermal stresses have been introduced into a ceramic piece, it is impossible to remove them.
T/F

Back 138

F

Front 139

Which of the following represents the correct phase transformation sequence as a glass material is heated?

Supercooled liquid; Solid; Liquid
Liquid; Supercooled liquid; Solid
Liquid; Solid; Supercooled liquid
Solid; Supercooled liquid; Liquid
Solid; Liquid; Supercooled liquid
Supercooled liquid; Liquid; Solid

Back 139

Solid; Supercooled liquid; Liquid

Front 140

The strength of a glass piece may be improved by inducing thermal compressive residual surface stresses.

T/F

Back 140

T

Front 141

Thermal tempering results in the introduction of

Compressive stresses on the surface.
Compressive stresses internally.
Tensile stresses on the surface.
Tensile stresses internally.

Back 141

Compressive stresses on the surface.

Tensile stresses internally.

Front 142

For the following pair of polymers do the following: indicate if it is not possible to determine if one polymer is more likely to crystallize the other. On the other hand, if it is possible to make such a determination then indicate which of the two is more likely to crystallize.

Not possible
Linear, syndiotactic poly(vinyl chloride)
Linear, isotactic polystyrene

Back 142

Linear, syndiotactic poly(vinyl chloride)

Front 143

For the following pair of polymers do the following: indicate if it is not possible to determine if one polymer is more likely to crystallize the other. On the other hand, if it is possible to make such a determination then indicate which of the two is more likely to crystallize.

Network phenol-formaldehyde; linear, heavily crosslinked cis-isoprene

Back 143

not possible

Front 144

For the following pair of polymers do the following: indicate if it is not possible to determine if one polymer is more likely to crystallize the other. On the other hand, if it is possible to make such a determination then indicate which of the two is more likely to crystallize.

Linear polyethylene; lightly branched isotactic polypropylene

Back 144

linear polyethylene

Front 145

For the following pair of polymers do the following: indicate if it is not possible to determine if one polymer is more likely to crystallize the other. On the other hand, if it is possible to make such a determination then indicate which of the two is more likely to crystallize.

Alternating poly(styrene-ethylene) copolymer; random poly(vinyl chloride-tetrafluoroethylene) copolymer

Back 145

Alternating poly(styrene-ethylene) copolymer

Front 146

Which of the following may form linear polymers?

Polystyrene
Nylon
Rubber
Epoxy
Polyethylene
Phenol-formaldehyde

Back 146

Polystyrene
Nylon
polyethylene

Front 147

Which of the following form network polymers?

Polystyrene
Nylon
Rubber
Epoxy
Polyethylene
Phenol-formaldehyde

Back 147

epoxy
phenol-formaldehyde

Front 148

Match the stereoisomer descriptions with their configuration classifications.

All R groups are on the same side.
R groups alternate sides of the chain.
R groups are randomly positioned along the chain.

Back 148

isotactic
syndiotactic
atatic

Front 149

Is it possible to grind up and reuse phenolformaldehyde?

Back 149

no

Front 150

For the following pair of polymers, do the following: (1) state whether or not it is possible to determine whether one polymer is more likely to crystallize than the other; (2) if it is possible, select which is the more likely to crystallize.

Linear and syndiotactic polypropylene
Crosslinked cis-isoprene

Back 150

Linear and syndiotactic polypropylene

Front 151

How do the densities of crystalline and amorphous polymers of the same material and having the same molecular weight compare?

density of crystalline polymer =density of amorphous polymer
density of crystalline polymer > Density of amorphous polymer
Density of crystalline polymer < density of amorphous polymer

Back 151

density of crystalline polymer > Density of amorphous polymer

Front 152

During a tensile test on a semicrystalline polymer, once a neck forms in the gauge section of the specimen, continued specimen elongation proceeds by

neck propagation along the specimen gauge length.
further neck constriction.

Back 152

neck propagation along the specimen gauge length.
further neck constriction.

Front 153

Significant tensile deformation of a semicrystalline polymer results in a highly-oriented structure.

T/F

Back 153

T

Front 154

How does annealing an undeformed semicrystalline polymer affect its yield strength?

increases/decreases

Back 154

increases

Front 155

How does each of the following influence the tensile or yield strength of a semicrystalline polymer?

(a) Molecular weight increase
(b) Degree of crystallinity increase
(c) Deformation by drawing
(d) Annealing of an undeformed material
(a) - non-direct influence, (b) - increase, (c) - decrease, (d) - increase
(a) - increase, (b) - increase, (c) - increase, (d) - increase
(a) - decrease, (b) - increase, (c) - decrease, (d) - decrease
(a) - increase, (b) - decrease,(c) - decrease, (d) - increase

Back 155

(a) - increase, (b) - increase, (c) - increase, (d) - increase

Front 156

Would you expect the tensile strength of polychlorotrifluoroethylene to be greater, the same as, or less than that of a polytetrafluoroethylene specimen having the same molecular weight and degree of crystallinity?

Back 156

greater

Front 157

List two molecular characteristics that are essential for elastomers.

(1) Elastomer must not easily crystallize and (2) the lowest temperature at which rubber-like behavior persists is between -50 and -90oC.
(1) Elastomers must experience a rise in temperature when stretched and (2) the modulus of elasticity decreases with increasing temperature.
(1) For elastomers to experience relatively large elastic deformations, the onset of plastic deformations must be delayed and (2) elastomers must have huge molecular weight.
(1) Elastomers must be amorphous, having chains that are extensively coiled and kinked in the unstressed state and (2) there must be some crosslinking.

Back 157

(1) Elastomers must be amorphous, having chains that are extensively coiled and kinked in the unstressed state and (2) there must be some crosslinking.

Front 158

For the following pair of polymers, decide whether or not it is possible to determine which has the higher tensile strength. If it is not possible, then click on the "not possible" button. If it is possible, then select the one with the higher strength.

Syndiotactic poly(vinyl chloride) with a degree of polymerization of 1000.
Atactic poly(vinyl chloride) with a degree of polymerization of 1000.

Atactic poly(vinyl chloride)
Syndiotactic poly(vinyl chloride)
Not possible

Back 158

Syndiotactic poly(vinyl chloride)

Front 159

For the following pair of polymers, decide whether or not it is possible to determine which has the higher tensile strength. If it is not possible, then click on the "not possible" button. If it is possible, then select the one with the higher strength.

Alternating styrene-butadiene copolymer having a weight-average molecular weight of 750,000 g/mol, with 15% of possible sites crosslinked.
Random styrene-butadiene copolymer having a weight-average molecular weight of 500,000 g/mol, with 10% of possible sites crosslinked.

Back 159

alternating

Front 160

For the following pair of polymers, decide whether or not it is possible to determine which has the higher tensile strength. If it is not possible, then click on the "not possible" button. If it is possible, then select the one with the higher strength.

Branched polyethylene with a number-average molecular weight of 100,000 g/mol.
Linear polyethylene with a number-average molecular weight of 80,000 g/mol.

Back 160

not possible

Front 161

How does increasing the degree of crystallinity of a semicrystalline polymer affect its tensile strength?

Back 161

increases

Front 162

How does increasing the molecular weight of a semicrystalline polymer affect its tensile strength?

Back 162

increases

Front 163

In order for a polymer to behave as an elastomer, which of the following is (are) necessary?

The polymer must be above its glass transition temperature.
Chain bond rotations must be relatively free.
The polymer must be below its glass transition temperature.
It must crystallize easily.
Chain bond rotations must not be relatively free.
It must not crystallize easily.

Back 163

The polymer must be above its glass transition temperature.
Chain bond rotations must be relatively free.
It must not crystallize easily.

Front 164

As the sulfur content of a rubber increases, its hardness

Back 164

increases

Front 165

Which polymerization technique generally has longer reaction times?

Addition polymerization
Condensation polymerization

Back 165

condensation

Front 166

Which polymerization technique is generally used to produce crosslinked and network polymers?

Addition polymerization
Condensation polymerization

Back 166

condensation

Front 167

Why are fillers added to polymers?

To improve tensile strength.
To improve compressive strength.
To improve toughness.
To improve thermal stability.
To improve flexibility.

Back 167

To improve tensile strength.
To improve compressive strength.
To improve toughness.
To improve thermal stability.

Front 168

Why are plasticizers added to polymers?

To improve compressive strength.
To improve thermal stability.
To improve toughness.
To improve flexibility.
To improve tensile strength.

Back 168

To improve toughness.
To improve flexibility.

Front 169

Amorphous thermoplastics are formed above their

Softening points.
Glass transition temperatures.
Melting temperatures.

Back 169

GTT

Front 170

Which of the following polymer types is more amenable to recycling?

Thermosetting
Thermoplastic

Back 170

thermoplastic

Front 171

For composite materials, which is phase is normally harder?

The dispersed phase
The matrix phase

Back 171

dispersed

Front 172

From the following numbered list of characteristics, decide which pertain to (a) precipitation hardening, and which are displayed by (b) dispersion strengthening.

(1) The strengthening mechanism involves the hindering of dislocation motion by precipitates/particles.
(2) The hardening/strengthening effect is not retained at elevated temperatures for this process
(3) The hardening/strengthening effect is retained at elevated temperatures for this process
(4) The strength is developed by a heat treatment
(5) The strength is developed without a heat treatment

Back 172

a) 1 2 4
b) 1 3 5

Front 173

For an aligned fibrous composite, when a stress is applied in a direction that is parallel to the fibers, what is the reinforcement efficiency?

Back 173

1

Front 174

For an aligned fibrous composite, when a stress is applied perpendicular to the fibers, what is the reinforcement efficiency?

Back 174

0

Front 175

From the following numbered list of mechanical characteristics, decide which pertain to (a) the matrix phase, and which are displayed by (b) the dispersed phase for fiber-reinforced composites.

(1) Stiff

(2) Relatively weak

(3) Low elastic modulus

(4) Brittle

(5) Quite ductile

(6) Quite strong

Back 175

a) 2 3 5

b) 1 4 6

Front 176

For the following pair of alloys that are coupled in seawater, predict the possibility of corrosion; if corrosion is probable, note which alloy will corrode.

brass (60Cu-40Zn) and monel (70Ni-30Cu)

Back 176

corrosion unlikely

Front 177

Metals near the top of the galvanic series are

Cathodic
Anodic
Unreactive
Reactive

Back 177

cathodic
unreactive

Front 178

Metals near the bottom of the galvanic series are

Cathodic
Anodic
Unreactive
Reactive

Back 178

aniodic
reactive

Front 179

Oxidation of an atom involves the

Back 179

loss of e-

Front 180

oxidation takes place at the

Back 180

annode

Front 181

Which of the following is/are oxidation reactions?

Fe --> Fe2+ + 2 e-
H2 --> 2 H+ +2 e-
Al --> Al3+ + 3 e-
2 H+ + 2 e- --> H2

Back 181

Fe --> Fe2+ + 2 e-
H2 --> 2 H+ +2 e-
Al --> Al3+ + 3 e-

Front 182

Reduction of an atom involves the

Back 182

gain of e-

Front 183

Reduction takes place at the

Back 183

cathode

Front 184

Which of the following are reduction reactions?
H2 --> 2 H+ +2 e-
Fe --> Fe2+ + 2 e-
Al --> Al3+ + 3 e-
2 H+ + 2 e- --> H2

Back 184

2 H+ + 2 e- --> H2

Front 185

Which of the following describes crevice corrosion?

Oxidation and reduction reactions occur randomly over the surface.
Corrosion that results from a difference in concentration of ions or dissolved gases in the electrolyte.
One element is preferentially removed as a result of corrosion.
Corrosion resulting from the combined action of chemical attack and mechanical abrasion or wear.
Two metals/alloys of different compositions are coupled while exposed to an electrolyte.
Corrosion resulting from the combined action of an applied tensile stress and a corrosive environment.
Corrosion that occurs preferentially along grain boundaries.
Localized corrosion that may be initiated at a surface defect.

Back 185

Corrosion that results from a difference in concentration of ions or dissolved gases in the electrolyte.

Front 186

Which of the following describes galvanic corrosion?

Corrosion that results from a difference in concentration of ions or dissolved gases in the electrolyte.
Corrosion resulting from the combined action of an applied tensile stress and a corrosive environment.
Oxidation and reduction reactions occur randomly over the surface.
Two metals/alloys of different compositions are coupled while exposed to an electrolyte.
Corrosion resulting from the combined action of chemical attack and mechanical abrasion or wear.
Localized corrosion that may be initiated at a surface defect.
Corrosion that occurs preferentially along grain boundaries.
One element is preferentially removed as a result of corrosion.

Back 186

Two metals/alloys of different compositions are coupled while exposed to an electrolyte.

Front 187

Which of the following describes pitting?

Corrosion that occurs preferentially along grain boundaries.
Oxidation and reduction reactions occur randomly over the surface.
Two metals/alloys of different compositions are coupled while exposed to an electrolyte.
Localized corrosion that may be initiated at a surface defect.
Corrosion that results from a difference in concentration of ions or dissolved gases in the electrolyte.
One element is preferentially removed as a result of corrosion.
Corrosion resulting from the combined action of chemical attack and mechanical abrasion or wear.
Corrosion resulting from the combined action of an applied tensile stress and a corrosive environment.

Back 187

Localized corrosion that may be initiated at a surface defect.

Front 188

Which of the following describes stress corrosion?

Corrosion resulting from the combined action of chemical attack and mechanical abrasion or wear.
Two metals/alloys of different compositions are coupled while exposed to an electrolyte.
Corrosion resulting from the combined action of an applied tensile stress and a corrosive environment.
Localized corrosion that may be initiated at a surface defect.
Corrosion that occurs preferentially along grain boundaries.
One element is preferentially removed as a result of corrosion.
Oxidation and reduction reactions occur randomly over the surface.
Corrosion that results from a difference in concentration of ions or dissolved gases in the electrolyte.

Back 188

Corrosion resulting from the combined action of chemical attack and mechanical abrasion or wear.

Front 189

Cathodic protection reduces the corrosion rate of a metal when an electrical connection is made to another metal that is

Higher in the galvanic series.
Lower in the galvanic series.

Back 189

Lower in the galvanic series.

Front 190

In most instances, one way to reduce the corrosion rate is to

Decrease the fluid temperature.
Increase the fluid temperature.

Back 190

Decrease the fluid temperature.

Front 191

Galvanizing involves applying a layer of what metal to the surface of steel?

Copper
Zinc
Iron
Nickel
Aluminum

Back 191

Zinc

Front 192

Polymer degradation may occur from exposure to or as a result of which of the following?



Radiation
Electrochemical reactions
Heat
Swelling
Physiochemical reactions

Back 192

Radiation
Heat
Swelling
Physiochemical reactions

Front 193

The swelling of a polymer results in it becoming

Harder
Softer

Back 193

softer

Front 194

olymer deterioration by swelling may be reduced by

Increasing the degree of crosslinking.
Decreasing the degree of crosslinking.
Increasing the molecular weight.
Decreasing the molecular weight.
Increasing the degree of crystallinity.
Decreasing the degree of crystallinity.

Back 194

Increasing the degree of crosslinking.
Increasing the molecular weight.
Increasing the degree of crystallinity.

Front 195

Are energies for electrons that participate in the conduction process (i.e., free electrons) greater or less than the Fermi energy?

Back 195

greater than

Front 196

An insulator has an energy band gap that is relatively

narrow.
wide.

Back 196

wide

Front 197

For nonmetallic materials, which of the following is true?

The wider the band gap, the higher the electrical conductivity at a given temperature.
The wider the band gap, the lower the electrical conductivity at a given temperature.

Back 197

The wider the band gap, the lower the electrical conductivity at a given temperature.

Front 198

Which of the following have a significant influence on a material's electrical resistivity?

Grain size
Cold work
Vacancy concentration
Impurity concentration
Temperature

Back 198

Cold work
Vacancy concentration
Impurity concentration
Temperature

Front 199

How do the electrical conductivities of metals compare with those of semiconductors?

σMetals > σSemiconductors
σMetals =σSemiconductors
σMetals < σSemiconductors

Back 199

σMetals > σSemiconductors