A creep resistant material should have

Choose one answer.

	a. a high elastic modulus.
	b. a high melting temperature.
	c. a high yield strength.
	d. a long fatigue life.

Question 2

A material has a melting point of 200 degrees Celsius, and we apply constant force loads at 20 degrees Celsius.

Choose one answer.

	a. We do not expect creep deformation to occur.
	b. Fast fracture should occur before creep deformation begins.
	c. We do expect creep deformation to occur.
	d. We do not have enough information to predict creep deformation.

Question 3

A "critical crack length" is associated with

Choose one answer.

	a. plastic yielding
	b. creep permanent strain.
	c. fast fracture.
	d. non-protective oxide films.

Question 4

A "ductile" material has a relatively high value of

Choose one answer.

	a. percent elongation.
	b. hardness.
	c. elastic modulus.
	d. ultimate tensile strength.

Question 5

A "stiff" material has a relatively high value of

Choose one answer.

	a. elastic modulus.
	b. Poisson's ratio.
	c. yield stress.
	d. tensile strength.

Question 6

A "strong" material has a relatively high value of

Choose one answer.

	a. shear modulus.
	b. yield stress.
	c. percent elongation.
	d. creep rate.

Question 7

Charpy and Izod are names associated with equipment used to measure

Choose one answer.

	a. hardness.
	b. yield strength.
	c. creep resistance.
	d. toughness.

Question 8

Creep deformation failure is a concern

Choose one answer.

	a. in jet engines.
	b. in automobile engines.
	c. with aircraft wings.
	d. with plastics at low temperatures.

Question 9

Creep deformation is particularly a concern

Choose one answer.

	a. at low temperatures.
	b. at high temperatures.
	c. when vibration is present.
	d. when materials are in an oxygen-rich environment.

Question 10

Failure by nucleation of surface cracks is particularly common with

Choose one answer.

	a. impact testing.
	b. fatigue testing.
	c. creep testing.
	d. tensile testing.

Question 11

Fast fracture

Choose one answer.

	a. is crack propagation at the speed of sound.
	b. is always preceded by plastic yielding.
	c. occurs only at low temperatures.
	d. is observed in ceramics, but never in metals.

Question 12

For ductile metals that strain harden, the tensile strength

Choose one answer.

	a. may be either less than or greater than the yield stress.
	b. is always less than the yield stress.
	c. is always greater than the yield stress.
	d. is not usually measured in the tensile test.

Question 13

For most solids (metals, ceramics, rigid plastics) elastic deformation

Choose one answer.

	a. is linear stress-strain behavior.
	b. is parabolic stress-strain behavior.
	c. obeys the Arrhenius law.
	d. results in permanent shape change.

Question 14

Hardness measurements

Choose one answer.

	a. can identify polymers.
	b. are completely non-destructive.
	c. cannot be made on ceramics.
	d. often follow heat treatment of metals.

Question 15

Hardness measurements are useful because the resulting hardness number can be correlated with the material property of

Choose one answer.

	a. yield stress.
	b. creep rate.
	c. fatigue life.
	d. stiffness.

Question 16

Linear oxidation rates are associated with

Choose one answer.

	a. brittle fracture.
	b. protective oxide films.
	c. non-protective oxide films.
	d. stainless steels.

Question 17

Materials described as "ductile"

Choose one answer.

	a. have low melting points.
	b. have a high percent elongation.
	c. have a low yield stress.
	d. have low percent area reduction values.

Question 18

Oxidation of metals

Choose one answer.

	a. is always corrosive.
	b. can sometimes be beneficial.
	c. doesn't occur with many metals.
	d. can be avoided by operating at high temperatures.

Question 19

Plastic deformation

Choose one answer.

	a. only occurs at elevated temperatures.
	b. is irreversible shape change.
	c. can sometimes be reversible shape change.
	d. always fractures the part.

Question 20

Preexisting micro cracks such as those found in sintered materials and large welded structures tend to promote failure by

Choose one answer.

	a. fast fracture.
	b. plastic yielding.
	c. excessive creep strain.
	d. non-protective oxide formation.

Question 21

Rockwell and Brinell are names associated with equipment used to measure

Choose one answer.

	a. stiffness.
	b. hardness.
	c. toughness.
	d. fatigue life.

Question 22

Some metals exhibit an "endurance limit" when loaded

Choose one answer.

	a. in a tensile test.
	b. in a fatigue test.
	c. in a creep test.
	d. in a hardness machine.

Question 23

Sometimes we do not try to stop electrochemical attack, but allow it to proceed by

Choose one answer.

	a. using materials with parabolic oxide growth rates.
	b. utilizing a sacrificial cathode.
	c. utilizing a sacrificial anode.
	d. using materials with linear oxide growth rates.

Question 24

The Arrhenius law is often found to describe

Choose one answer.

	a. final hardness.
	b. cycles to failure.
	c. impact strength.
	d. temperature variations.

Question 25

The label of "hardening" is often used to describe the process of

Choose one answer.

	a. annealing.
	b. straining.
	c. melting.
	d. strengthening.

Question 26

The sliding deformation of shear

Choose one answer.

	a. always results in a decrease in volume.
	b. occurs with constant volume.
	c. always results in an increase in volume.
	d. can either increase or decrease the volume.

Question 27

The Standard Electrode Potential and Galvanic Series give information about

Choose one answer.

	a. wet corrosion rates.
	b. protective oxide films.
	c. cathode and anode identification.
	d. corrosion electrical currents.

Question 28

The units of mechanical stress are

Choose one answer.

	a. meters squared (or feet squared).
	b. dimensionless.
	c. newtons/meters squared (or pounds per square inch).
	d. newtons (or pounds).

Question 29

The units of Poisson's ratio are

Choose one answer.

	a. pascals.
	b. seconds.
	c. meters squared.
	d. dimensionless.

Question 30

The units of the stress intensity factor are

Choose one answer.

	a. pascals.
	b. pascals times square root of meters.
	c. percent per square meter.
	d. dimensionless.

Question 31

The units plotted on an S-N curve are

Choose one answer.

	a. stress versus cycles.
	b. stress versus strain.
	c. strain versus time.
	d. mass gain versus time.

Question 32

To minimize the rate of wet corrosion we should

Choose one answer.

	a. minimize the cathode area.
	b. minimize the anode area.
	c. make the anode and cathode areas as nearly equal as possible.
	d. ignore areas as corrosion rate is not strongly dependent on area.

Question 33

Which of the following promotes longer fatigue life?

Choose one answer.

	a. Residual tensile stresses in the surface
	b. Sharp corners in the sample geometry
	c. Rough surface texture
	d. Residual compression stresses in the surface

Question 34

With surface treatments to a material, we can significantly

Choose one answer.

	a. decrease creep strain rate.
	b. increase stiffness.
	c. increase impact energy absorption.
	d. lengthen fatigue life.

Question 35

"Brittle" materials exhibit

Choose one answer.

	a. plastic deformation followed by elastic deformation.
	b. elastic deformation followed by plastic deformation.
	c. elastic deformation only.
	d. plastic deformation only.

Question 36

"Strain Hardening" refers to

Choose one answer.

	a. necking down of polymer materials.
	b. a property of brittle materials.
	c. an increase in yield stress.
	d. an increase in stiffness.

Question 37

A disadvantage of aluminum alloys is that they

Choose one answer.

	a. show creep deformation at relatively low temperatures.
	b. oxidize rapidly.
	c. cannot be alloyed to be heat treatable.
	d. have low thermal conductivity.

Question 38

A disadvantage of ceramics is they

Choose one answer.

	a. often interact with atmospheres.
	b. can be difficult to shape.
	c. tend to deform by creep.
	d. lose their ductility at low temperatures.

Question 39

A disadvantage of titanium alloys is that

Choose one answer.

	a. they are relatively expensive.
	b. they are chemically reactive.
	c. they have high strength to weight ratios.
	d. they cannot be heat treated.

Question 40

An advantage of ceramics is that

Choose one answer.

	a. they are typically very hard.
	b. they can easily be formed into complex shapes.
	c. they have high percent elongation.
	d. they have high densities.

Question 41

An advantage of polymers is that

Choose one answer.

	a. they usually have high melting temperatures.
	b. they are hard and scratch resistant.
	c. they have low elastic modulus values.
	d. they are usually chemically inert.

Question 42

At the glass transition temperature, thermoplastic polymers

Choose one answer.

	a. show a volume change like melting ice.
	b. change color.
	c. change smoothly between rigid solid and viscous liquid.
	d. permanently set up into rigid solids.

Question 43

Cermets are composites of ceramic and metal. We would expect the resulting material to be

Choose one answer.

	a. brittle and electrically insulating.
	b. tough and hard.
	c. flexible and high melting.
	d. low density and soft.

Question 44

Covalent bonds

Choose one answer.

	a. result in ions packing close together.
	b. are consistent with the high electrical conductivity of metals.
	c. are easily broken during plastic deformation.
	d. result in lower density solids.

Question 45

Cross-linking a thermoplastic polymer

Choose one answer.

	a. stiffens it.
	b. causes it to flow more freely.
	c. increases the glass transition temperature.
	d. improves oxidation resistance.

Question 46

During the "tempering" process of quench hardened steels

Choose one answer.

	a. a hard, strong phase forms.
	b. the steel softens slightly.
	c. oxide formation is reduced.
	d. the operating temperature of the final steel product is increased.

Question 47

Engineering composites are often GRPR and CRPR, with the PR standing for

Choose one answer.

	a. polycrystalline reinforced.
	b. particle remelted.
	c. polymer resins.
	d. plastic remolded.

Question 48

Low carbon or mild steels

Choose one answer.

	a. are always quench hardened.
	b. are the construction I-beam steels.
	c. have particularly good corrosion resistance.
	d. have relatively large amounts of other alloying elements.

Question 49

Metals that exhibit high thermal conductivity generally

Choose one answer.

	a. have low densities.
	b. have high melting temperatures.
	c. exhibit low electrical conductivity.
	d. also exhibit high electrical conductivity.

Question 50

Most often, engineering composites are chosen for

Choose one answer.

	a. isotropic behavior (same in all directions).
	b. light weight.
	c. high melting temperature.
	d. low cost.

Question 51

Oxides, nitrides, and silicates predominate in

Choose one answer.

	a. polymers.
	b. ceramics.
	c. composite materials.
	d. metals.

Question 52

Some polymers are rubbery because

Choose one answer.

	a. covalent bonds readily stretch.
	b. long chain molecules can uncoil and recoil.
	c. polymer molecules easily slide over one another.
	d. ionic bonds are easily broken.

Question 53

The nature of metallic bonding accounts for

Choose one answer.

	a. the light weight of some metals.
	b. the high electrical and thermal conductivities of most metals.
	c. the tendency of metals to corrode.
	d. the brittleness of some metals.

Question 54

The quench process in precipitation-hardened alloys

Choose one answer.

	a. results in a hard structure.
	b. results in a soft structure.
	c. causes a phase change within the alloy.
	d. is required to clean the alloy surface.

Question 55

Thermoplastic polymers

Choose one answer.

	a. are rubbery materials.
	b. are permanent once cured.
	c. are usable to higher temperatures than other polymers types.
	d. can be repeatedly softened and stiffened.

Question 56

Thermosetting polymers

Choose one answer.

	a. are recyclable.
	b. are frequently rubber-like.
	c. include the hard, rigid Bakelite® and melamine plastics.
	d. are usually clear or translucent.

Question 57

To operate at the highest temperature, the materials class most often chosen is

Choose one answer.

	a. composite materials.
	b. metals.
	c. polymers.
	d. ceramics.

Question 58

To resist shattering on sudden temperature change, it is desirable that glasses

Choose one answer.

	a. have low thermal expansion coefficients.
	b. have high thermal expansion coefficients.
	c. have high softening temperatures.
	d. have low densities.

Question 59

Which of the following is not a composite material?

Choose one answer.

	a. Nickel-based super alloy turbine blade
	b. Wood
	c. Reinforced concrete
	d. Graphite reinforced tennis racket frame.

Question 60

"Porous" ceramics include

Choose one answer.

	a. tungsten carbide tool inserts.
	b. porcelain plates.
	c. silicon carbide abrasives.
	d. diamonds.

Question 61

A material with a relatively low value of impact energy absorbed

Choose one answer.

	a. is considered to be ductile.
	b. is considered to be brittle.
	c. is most likely low density.
	d. is most likely of a low melting temperature.

Question 62

A predictor of creep deformation is a material's

Choose one answer.

	a. endurance limit.
	b. hardness number.
	c. melting or softening temperature in kelvin.
	d. elastic stiffness.

Question 63

As a ductile metal is plastically deformed at cooler temperatures

Choose one answer.

	a. its elastic stiffness increases.
	b. its melting temperature decreases.
	c. its yield stress increases.
	d. its volume increases.

Question 64

Crack detection by x-rays or chemical techniques is particularly important if it is suspected that failure might occur by

Choose one answer.

	a. creep.
	b. plastic yielding.
	c. fast fracture.
	d. oxidation.

Question 65

Creep deformation is particularly a concern

Choose one answer.

	a. when corrosion is occurring.
	b. at low temperatures.
	c. at high temperatures.
	d. when vibration is present.

Question 66

For a metal that work hardens severely

Choose one answer.

	a. the elastic modulus is very low.
	b. the percent elongation is very high.
	c. the tensile strength is much higher than the yield stress.
	d. the tensile strength is much lower than the yield stress.

Question 67

Generally we find maximum toughness to fast fracture with

Choose one answer.

	a. metals.
	b. plastics.
	c. ceramics.
	d. composite materials.

Question 68

If a material is to bend before it breaks, a relevant material property is

Choose one answer.

	a. rupture modulus.
	b. elastic modulus.
	c. hardness number.
	d. percent elongation.

Question 69

If elastic deformation is to be a minimum, then

Choose one answer.

	a. we should select the material with the highest elastic modulus.
	b. we should select the material with the highest melting temperature.
	c. we cannot generalize without knowing the geometry of the part.
	d. we should select the material with the highest yield strength.

Question 70

If our part must be light weight, then lacking other design constraints, our choice would most likely be a

Choose one answer.

	a. plastic.
	b. metal.
	c. ceramic.
	d. composite material.

Question 71

Many steels exhibit an "endurance limit" when tested in

Choose one answer.

	a. creep.
	b. impact.
	c. fatigue.
	d. tension.

Question 72

The class of materials stable to the highest temperatures is

Choose one answer.

	a. metals.
	b. polymers.
	c. composite materials.
	d. ceramics.

Question 73

The flexed rotating beam apparatus compares materials in

Choose one answer.

	a. fatigue failure.
	b. creep failure.
	c. stress corrosion.
	d. elastic recovery.

Question 74

The stress-strain curve of an elastomer (rubber-like material) is usually

Choose one answer.

	a. linear.
	b. non-linear.
	c. restricted to approximately 0.2% strain.
	d. showing a higher elastic modulus than for most metals.

Question 75

The units of specific gravity are

Choose one answer.

	a. kg/m³.
	b. kilograms.
	c. m/s².
	d. dimensionless.

Question 76

To minimize creep rate, it is desirable to have metals

Choose one answer.

	a. with fine (small) grains.
	b. with coarse (large) grains.
	c. with high yield strengths.
	d. with low melting temperatures.

Question 77

To predict fast fracture, materials are compared in terms of

Choose one answer.

	a. critical stress intensity factor.
	b. hardness number.
	c. density.
	d. melting temperature.

Question 78

To slow electrochemical attack

Choose one answer.

	a. the cathode areas should be small.
	b. the anode areas should be small.
	c. metals should be widely separated in the electrochemical series.
	d. surfaces should be rough rather than smooth.

Question 79

Which of the following in not a condition for electrochemical attack?

Choose one answer.

	a. Non-protective oxide film
	b. Contact with an aqueous solution
	c. Electrical contact between anode and cathode
	d. Two dissimilar metals

Question 80

Which of the following is not a way to improve fatigue life?

Choose one answer.

	a. Using polished surfaces
	b. Strain hardening
	c. Introducing compressive surface residual stresses
	d. Reducing geometries of sharp corners

Question 81

With electrochemical attack, the dissolving metal is

Choose one answer.

	a. more dense metal.
	b. the standard electrode.
	c. the cathode.
	d. the anode.

Question 82

With fatigue failure, micro cracks grow until the part fails by

Choose one answer.

	a. creep.
	b. fast fracture.
	c. excessive plastic deformation.
	d. necking down to concentrate stress.

Question 83

With galvanized sheet (zinc on steel)

Choose one answer.

	a. the iron is the sacrificial anode.
	b. the zinc is the sacrificial anode.
	c. either iron or zinc can be the anode.
	d. both the iron and zinc corrode simultaneously.

Question 84

"Ductile" materials have

Choose one answer.

	a. high percent elongation.
	b. low yield strength.
	c. low melting temperatures.
	d. low density.

Question 85

A disadvantage of mechanical forming is that

Choose one answer.

	a. though stronger, final parts are also more brittle.
	b. long rod and tube shapes cannot be formed.
	c. it cannot be used with materials at high temperatures.
	d. porous, low density products may result.

Question 86

A disadvantage of sintering is that

Choose one answer.

	a. parts are generally limited to be small in size.
	b. porous, low-density products may result.
	c. preferred textures may be in the final products.
	d. only low-temperature materials can be formed this way.

Question 87

A limitation of forming by casting is that

Choose one answer.

	a. chemically reacting materials cannot be cast.
	b. extensive post machining may be required.
	c. some materials deteriorate before they melt.
	d. porous, low-density products may result.

Question 88

A process capable of forming an intricate geometrical shape is

Choose one answer.

	a. directional solidification.
	b. preferred orientation stamping.
	c. oxyacetylene torch cutting.
	d. lost wax casting.

Question 89

An advantage of forming by casting is

Choose one answer.

	a. the porous product can be utilized for specialized applications.
	b. dissimilar materials can be joined together.
	c. metals can be strengthened while being shaped.
	d. intricate shapes can be formed in a single step.

Question 90

An advantage of forming by mechanical deformation is

Choose one answer.

	a. dissimilar materials can be joined together.
	b. intricate shapes can be formed in a single step.
	c. the porous product can be utilized for specialized applications.
	d. metals can be strengthened while being shaped.

Question 91

An advantage of forming by sintering is

Choose one answer.

	a. refractory (very high melting) materials can be shaped.
	b. metals can be strengthened while being shaped.
	c. dissimilar materials can be joined together.
	d. preferred texture can be imparted to the final part.

Question 92

An advantage of MIG (metal-inert-gas) welding is

Choose one answer.

	a. dissimilar materials can be joined together.
	b. it can be used to cut as well as join metals.
	c. acetylene gas is explosive.
	d. it can be automated for use with industrial robots.

Question 93

Caution must be used with sintering because

Choose one answer.

	a. very fine powders can be explosive.
	b. large electrical currents pass through the parts.
	c. temperatures involved are higher than the melting temperatures.
	d. corrosive chemicals are required.

Question 94

Ceramics are most often shaped by

Choose one answer.

	a. casting.
	b. sintering.
	c. compressive mechanical forming.
	d. TIG welding.

Question 95

Common "stick welding" is more formally known as

Choose one answer.

	a. MIG welding.
	b. TIG welding.
	c. oxyacetylene welding.
	d. shielded metal arc welding.

Question 96

Dislocations in metals are

Choose one answer.

	a. displaced grain boundaries.
	b. linear geometric defects.
	c. impurity concentrations.
	d. responsible for elastic deformation.

Question 97

The heat affected zone in welded stainless steels

Choose one answer.

	a. refers to the weld filler metal.
	b. is stronger than the surrounding metal.
	c. is severely work hardened.
	d. may no longer be corrosion resistant.

Question 98

Thermosetting polymers are frequently shaped by

Choose one answer.

	a. casting.
	b. extrusion.
	c. TIG welding.
	d. hot rolling.

Question 99

When a cold worked metal is annealed,

Choose one answer.

	a. its yield stress increases.
	b. its fracture toughness is decreased.
	c. recrystallization grows new grains within the metal.
	d. its dislocation density is increased.

Question 100

Which statement does not apply to TIG welding?

Choose one answer.

	a. It frequently is used to cut as well as join.
	b. The tungsten electrode is not consumed during the welding.
	c. TIG requires greater operator skill than other welding processes.
	d. It is usually the first choice for joining stainless steels.