Final Exam
In the BCC unit cell, the atoms are "touching" along the"
Body Diagonals
The number of immediately adjacent (i.e. touching) atoms to a given atom is called the:
Coordination number
Because of the range of colors, alloys of this metal are often used in architectural and artistic applications.
Copper
Which of the following is NOT considered to be an elevated temperature material?
Copper
Bonds of this type tend to be "directional", and the limited number of nearest neighbors often leads to light weight (low density) materials.
Covalent
The overwhelming majority of all mechanical component failures occur as a result of:
Fatigue
Cast irons are alloys of: A. Fe-Si-Cr B. Fe-C-Si C. Fe-C-Cr D. Fe-Cr-Ni
Fe-C-Si
To achieve homogeneous nucleation generally would require
undercooling of about .2 times the melting point on an absolute scale
This material has "better corrosion resistance to more media than any other commercial alloy".
Monel
This metal has good strength and corrosion resistance at elevated temperatures coupled with good formability (due to its FCC structure).
Nickel
Cast irons are alloys of iron with:
Si & C
The two most common mechanisms for atom movement (diffusion) are:
Vacancy and interstitial
When alloy elements are added to steel, they can:
all of these
Annealing operations can be used to:
all of these.
The 8620 steel is a:
alloy steel
The 8620 steel is a:
alloy steel.
Solid solution strengthening is a strengthening mechanism in
alloys
The portion of a metal part with the highest residual stresses will act as the:
anode
The fibers in a fiber-reinforced composite can be:
any
The hardness of a steel at the zero Jominy distance location (on the quenched end) is a good indication of the:
carbon content of the steel
The portion of a deformed metal part with the lowest residual stresses will act as the:
cathode
Introduction of tungsten carbide or tantalum carbide in a cobalt matrix is an example of:
cermets
In this region in a casting many small grains form due to rapid nucleation
chill
Sensitization of a stainless steel means that:
chromium carbides have formed at grain boundaries
Thousands of small dispersed voids can form when numerous small pockets of liquid are trapped during
dendritic growth
If the Ac-40%Bg alloy were to be cooled under rapid cool (non-equilibrium) conditions, the structure of the non-equilibrium solidified alloy would
exhibit some form of segregation
Three phase reactions appear as a ____ in a two component phase diagram
horizontal line
(Lead-Tin (Pb-Sn) diagram) -- The 30% tin alloy would be considered to be
hypoeutectic
In the Jominy test, the cooling rate of the material can be directly correlated to the:
location on the specimen
The activation energy would be lower (diffusion is easier) for which of these?
low melting point metal
The critical resolved shear stress is greatest in ___ materials. Hence, it provides the highest strength.
BCC
The composition of the pearlite that forms in a 0.6% C steel is:
.77% C
Using the AISI-SAE designation system for steels, the carbon content of an 8620 steel is about:
0.20%C
The packing factor for the simple cubic structure is:
0.52
(Lead-Tin (Pb-Sn) diagram) -- If a 61.9% tin alloy were equilibrium cooled to room temperature, we would expect to find a structure of
100% eutectic structure
If we cool a eutectiod composition steel (.77% C) under near-equilibrium conditions, the resulting microstructure will be: A. 100% pearlite B. 50% pearlite and 50% ferrite C. 75% pearlite and 25% ferrite D. 100% ferrite
100% pearlite
The coordination number for a face-centered cubic (FCC) structure is
12
For the Ac-40%Bg alloy, the amount of solid that has formed upon cooling to 600 C is
20%
The amount of primary ferrite in a 0.60% C steel (under equilibrium conditions) would be:
25%
(Lead-Tin (Pb-Sn) diagram) -- The liquidus temperature for the 30% tin alloy is closest to
260
The functionality of polymer reactants that form 3-dimensional network polymers is:
3+
(Lead-Tin (Pb-Sn) diagram) -- The eutectic structure is a mix of alpha and beta phases. The fraction of alphas phase is approximately
45%
Iron has a melting temperature of 1538oC. Diffusion becomes significant when iron is heated above: [NOTE: This may not be as straight-forward as you think!!]
451oC
The maximum solubility of copper in aluminum at elevated temperature is:
5.65% Cu
The coordination number for the simple cubic arrangement is:
6
The composition of the primary cementite that forms in a 1.2% C steel would be:
6.67% C
For the Ac-40%Bg alloy, the amount of liquid remaining at 500 C is
60%
Tool steels are designated by: A. a letter-number combination where the letter indicated "family" B. a four-digit AISI-SAE number based on chemistry and carbon content
A letter-number combination where the letter indicated "family"
The three-phase reaction in which γ à α + Fe3C is denoted as the ___ line in the phase diagram:
A1
If a steel has a Ductile-to-Brittle Transition Temperature (DBTT), it is best if it is used A. above this temperature B. Below this temperature
Above this temperature
The high hardness of ceramic materials make them excellent candidate materials for use as: A. Refractories B. Electrical and magnetic components C. Whiteware D. Abrasives
Abrasives
Materials that can exist in more than one crystal structure (depending upon the conditions of temperature and pressure) are called polymorphic (many-structured). Another term for this feature is:
Allotropic
A steel with a AISI-SAE designation of 4320 is a: A. Plain-carbon steel B. Alloy steel
Alloy steel
As a result of the ____ crystal structure, iron and steel at room temperature exhibit unusually high strength.
BCC
In the body-centered cubic (BCC) crystal structure, atoms touch (are in contact) along the:
Body diagonals
A steel gear is heated to diffusion temperatures in a furnace with a high-carbon-atmosphere. As time passes, the:
Carbon will diffuse into the surface of the steel.
The process described in question 22 ("A steel gear is heated to diffusion temperatures in a furnace with a high-carbon-atmosphere") is known as:
Carburizing
Inducing extensive branching of the chains would _______ the strength of a polymer.
Decrease
A high activation energy means that diffusion is:
Difficult
This type of cast iron, that offers properties closest to steels, contains smooth-surface graphite spheres that form directly upon solidification. A. Gray B. White C. Malleable D. Ductile E. Compacted graphite
Ductile
This NDT technique can only be used on electrically conductive materials.
Eddy Current Testing
The "ductility" of a material can be determined by which two tensile test properties?
Elongation and reduction in area
The "ductility" of a material can be measured by which two tensile test properties? A. Young's modulus and tensile strength B. Tensile strength and elongation C. Elongation and reduction in area D. Elongation and Young's modulus
Elongation and reduction in area
The activation energy (the Q in the D = Do e -Q/RT equation) is a measure of the:
Energy required to cause an atom to move position within a crystal
(Hypothetical Phase Diagram) -- Reaction at 750 C
Eutectic
Aluminum, copper and silver are typically soft, weak, and ductile metals. These are characteristics of which crystal structure?
FCC
Low thermal expansion is a characteristic or description of most polymeric materials.
False
To form smaller, more numerous grains and a stronger material, the cooling rate should be: A. Fast B. Slow
Fast
Ninety percent of all mechanical component failures occur as a result of : A. Tensile B. Impact C. Fatigue D. Creep
Fatigue
The room-temperature (BCC) form of iron that can only contain up to 0.02% carbon in solid solution is called:
Ferrite.
The crystalline ceramics are brittle becasue: A. Their structures do not contain dislocations B. Fracture occurs at a lower stress than dislocation movement C. The structures involve highly cross-linked molecules
Fracture occurs at a lower stress than dislocation movement
Crystalline defects are generally classified by their:
Geometry
Inoculation is a means of inducing:
Heterogeneous nucleation
Which of the following is NOT a characteristic of gray cast iron? A. Good resistance to sticking (adhesive) wear B. Good sound and vibration damping C. High fracture resistance D. Good machinablity
High fracture resistance
The tests done at Missouri S&T (then UMR) to investigate the brittleness of the hull plate steel from the HMS Titanic was this type of test:
Impact
The tests done at Missouri S&T (then UMR) to investigate the brittleness of the hull plate steel from the HMS Titanic were this type of test: A. Tensile B. Impact C. Fatigue D. Creep E. Hardness
Impact
This test can be used to determine if a metal has a ductile-to-brittle transition temperature.
Impact test
If we increase "hardenability" we: A. Increase the Rockwell C hardness B. Increase the ease of forming martensite
Increase the ease of forming martensite
Adding imperfections to a commercial metal (one that already contains defects) will almost always __ the strength and __ the ductility. A. Increase, increase B. Increase, decrease C. Decrease, increase D. Decrease, decrease
Increase, increase
A ferritic stainless steel is one that: A. Contains significant amounts of carbon and achieves much of its strength from phase transformation hardening B. Is the cheapest, and if it achieves most of its strength from solid solution strengthening C. Offers the greatest ductility and formability (because of its FCC crystal structure)
Is the cheapest, and if it achieves most of its strength from solid solution strengthening
Because of their geometries, the properties of ____ composites are always anisotropic A. Laminar B. Particulate C. Fiber reinforced
Laminar
This metal has the lowest density of all of the engineering metals (i.e. is the lightest engr. metal).
Magnesium
When we need useful strength and corrosion resistance at elevated temperature, we might want to consider alloys of: A. Aluminum B. Copper C. Nickel D. Magnesium
NIckel
Which of the following is NOT a refractory metal?
Nickel
Since glass is a(n) ___ structure, its formation requires cooling at a rate that is ____ than some critical value. A. Equilibrium, slower B. Equilibrium, faster C. Nonequilibrium, slower D. Nonequilibrium, faster
Nonequilibrium, faster
Copper and zinc are similar-size atoms. If zinc atoms are added to copper, they would be expected to: A. Occupy interstitial sites B. Occupy substitutional sites. C. Become vacancies
Occupy Substitutional sites
Compared to cold working, hot working:
Offers almost unlimited ductility
The efficiency of filling available space (% occupied) can be evaluated by computing the:
Packing Factor
Because of their geometries, the properties of ____ composites are always isotropic. A. Laminar B. Particulate C. Fiber reinforced
Particulate
The lamellar or layered structure, consisting of alternating plates of ferrite and cementite, is called: A. Cementite B. Pearlite C. Austenite D. Ferrite
Pearlite
The microstructure that forms above the "nose" in a eutectoid steel T-T-T diagram is: A. Pearlite B. Bainite C. Martensite
Pearlite
MicroCT is a type of this NDT technique.
Radiographic Imaging
During which stage of annealing are the residual stresses produced during cold working eliminated, but the strengthening of strain hardening is retained?
Recovery
The Hume-Rothery rules for unlimited solid solubility between two metals include all of these similarities EXCEPT: A. Same crystal structure B. Similar electronegativity or valence C. Similar strength D. Similar atomic radii
Similar strength
Many ceramic and powder metallurgy products are made by pressing solid particles to a desired shape and then heating the compacted material so diffusion can bond the particles to one another. This process is called:
Sintering
If a layer is out of sequence in the ABCABC stacking (such as ABCABABC), the defect is called a:
Stacking fault
A vertical line that appears in the middle of a diagram most likely represents a
Stoichiometric intermetallic
If we increase the temperature of a tensile test specimen we would expect ___ to increase. A. Yield strength B. Tensile strength C. Elastic modulus D. Reduction in area
Tensile strength
In Fick's First Law, J = -D (dc/dx), the term "D" represents:
The diffusion coefficient
In the plastic region of the tensile test: A. The material is always getting stronger B. The material gets stronger only up to the tensile strength C. The material gets weaker due to dislocation movement
The material is always getting stronger
What temperature is typically utilized during hot working?
The material's recrystallization temperature
In a standard tensile test, the material response during the elastic portion is due to:
The stretching of atomic bonds
During a tensile test, this is the highest value attained by the engineering stress:
The ultimate tensile strength
Which mechanical fastening method was predominantly utilized in applications experiencing a tensile loading in the TUDelft video "Introduction to the Types of Mechanically Fastened Joints "
Threaded Fasteners
Since it is strong, light weight and corrosion resistant to body fluids, orthopedic implants and bone-repair screws and plates often use this material.
Titanium
Ease of fabrication is a characteristic or description of most polymeric materials.
True
Good chemical and thermal stability is a property that is characteristic or descriptive of most ceramic materials.
True
This NDT technique utilizes vibrations or sound waves to detect defects.
Ultrasonic Testing
Tool steels are designated by
a letter-number combination where the letter indicates "family".
When two phases are present in a material, the relative amounts can be determined by
a lever law calculation
Cermets gain their enhanced toughness through:
a metal matrix.
NASA's EBF3 (Electron Beam FreeForm Fabrication) system utilizes:
a wire feeder
The most effective strengthening method for aluminum alloys is:
age hardening.
Which of the following is NOT a correct statement
all liquids are completely soluble in one another
Because it is similar to casting, the once molten metal region (fusion zone) of a fusion weld can experience which of the following problems
all of the above
Sites of preferential nucleation include
both a and b
We can promote the nucleation of a solid by
both a and b
To fully characterize an engineering material we must specify or describe
chemistry, temperature, pressure and full processing history (from solidification)
Suppose we introduce chromium whiskers into a nickel matrix to form a fiber- reinforced composite. Which component would act as the anode in a corrosive environment?
chromium whiskers
The fracture resistance of a ceramic can be best improved by:
decreasing the flaw size.
The size of this region in a casting can be increased by inoculation
equiaxed
If the same metal or alloy were cooled under equivalent cooling conditions, we would expect:
equivalent structures and properties
Cast irons are alloys that experience this three-phase reaction upon cooling.
eutectic
The three-phase reaction that is of primary importance in establishing the structure and properties of steel is the:
eutectoid
The three-phase reaction that is of primary importance in establishing the structure and properties of steel is the:
eutectoid.
The production of an amorphous structure requires
extremely fast cooling
The primary or pro-eutectoid phase that forms when we cool between the A3 and A1 temperatures is:
ferrite
The room-temperature (BCC) form of iron that can only contain up to 0.02% carbon in solid solution is called:
ferrite
The "deformation mechanism" associated with superplastic behavior is:
grain boundary sliding.
Compacted graphite cast iron has a structure and properties that fall between:
gray and ductile
Because it is a stoichiometric intermetallic compound, cementite has the following properties:
hard and brittle
When particles of a new phase nucleate from a solid solution under equilibrium conditions, they tend to nucleate:
heterogeneously on grain boundaries or other impurities
If a small amount of cold work produces a large increase in strength, the strain hardening coefficient, n, would be ___.
high
A below-room-temperature cooling may be necessary to complete the martensite transformation in
high carbon steels
Tool steels are:
high carbon steels, usually heat-treated to high hardness.
The rule of mixtures for composites does NOT work well in predicting:
impact properties
If we deform a metal in successive increments the yield strength will incrementally
increase
If we increase "hardenability", we:
increase the ease of forming martensite
According to Schmid's Law = Cos Cos , the most favorable condition for slip to occur is:
lamda=phi= 45
Copper has an atomic radius of 1.278 angstroms. According to the Hume-Rothery rules, which of the following elements would have the highest solubility in copper.
nickel (1.243 A)
The electrical resistance heating wires for toasters are often made from this material:
nickel-chromium.
To produce an amorphous solid we would need
no nucleation
The best corrosion resistance is found in alloys that are:
non-heat-treatable.
If the liquid ahead of a growing solid has a temperature higher than the melting point, growth into the liquid will be
planar growth
Selective Laser Melting (SLM) typically uses:
powder bed
Selective Laser Sintering (SLS) typically uses:
powder bed
If we want to produce the greatest solid solution strengthening with a 5% alloy addition to copper, it would be best if the atoms of the 5% alloy were
quite different in size from copper
Wrought alloys are:
shaped as a solid.
Which of the following similarities is NOT part of the Hume-Rothery rules
similar strength
The flame hardening of high-carbon steel is an example of a(n) ___ surface treatment.
single chemistry - dual heat treatment
This heat treatment of steel is used to improve the machinability of high carbon steels (>0.6%C):
spheroidize
Cementite (Fe3C) is a
stoichiometric intermetallic compound
Dmitri Mendeleev's 1869 publication of an early version of the Periodic Table of the Elements resulted in:
the discovery of several new elements
Which of the following will not help optimize the properties of a dispersion strengthened composite?
the dispersant must have a high solubility in the matrix
Iron has a higher density than iron oxide, therefore:
the oxide flakes off and oxidation continues
Iron oxide has a lower density than iron, therefore:
the oxide flakes off and oxidation continues
The Rule of Mixtures predicts properties based on:
the volume fractions of the component materials
The designation scheme for cast aluminum alloys involves a:
three-digit number.
If we heat a cold worked material into the diffusion range, the cold worked structure:
will change with time.
The composition of pearlite is always:
.77% C
(Lead-Tin (Pb-Sn) diagram) -- The maximum solubility of tin in lead is
19%
The portion of a metal part in contact with the lowest oxygen electrolyte will act as the:
Anode
Which of the following crystal structures does NOT contain close-packed planes?
BCC
Increase
Increase
Which of these composite joining techniques would be the fastest?
Ultrasonic Welding
(Lead-Tin (Pb-Sn) diagram) -- If an alloy with 10% tin is in equilibrium cooled to room temperature, we would expect a final structure of
an alpha phase matrix with beta phase precipitates
Which of these is not a benefit of selective laser sintering?
only low melting point powders may be used
A fine-grained metal will corrode slightly faster than the same metal with larger grains because of a:
stress cell
In dispersion hardening, it is best if the dispersed phase is
strong and hard
If we were to add 5% nickel to pure copper to produce copper 5% nickel alloy, the resulting alloy would be ____ and ____ than copper.
stronger
Cementite has ___ ductility.
zero
Aluminum and aluminum alloys are:
"fabrication friendly".
(Lead-Tin (Pb-Sn) diagram) -- The amount of eutectic microstructure that will be present in the 30% tin alloy can be computed by
(30-19)/(61.9-19)
(Lead-Tin (Pb-Sn) diagram) -- The amount of PRIMARY alpha that forms in the 30% tin alloy can be computed as
(61.9-30)/(61.9-19)
The composition of the primary ferrite that forms in a .4% C steel is: A. 6.67% C B. 2.11% C C. .77% C D. .02% C
.02% C
The primary ferrite in a 0.60% C steel would have a composition of:
.02% C
The maximum solubility of copper in aluminum at room temperature is about:
.02% Cu
We can estimate the temperature where diffusion becomes significant as: A. The melting point of the material B. 1000 Centigrade C. .4 times the melting point in absolute temp. D. .2 times the melting point when expressed in Centigrade
.2 times the melting point when expressed in Centigrade
The carbon content of a 4320 steel is about: A. .2% C B. 2.0% C C. .43% C D. 4.3% C
.2% C
Using the AISI-SAE designation system for steels, the carbon content of an 8620 steel is about
.2% C
The composition of pearlite is always: A. 6.67% B. 2.11% C. .77% D. .02%
.77%
When we heat a material, we can estimate the temperature where diffusion becomes significant as:
0.4 times the melting point in absolute temp.
The packing factor for the BCC crystal structure is:
0.68
The packing factor (packing efficiency) of the FCC crystal structure is:
0.74
The packing factor (packing efficiency) of the HCP crystal structure is:
0.74
number of atoms or lattice points fully-contained in a simple cubic unit cell is:
1
The fraction of a corner atom that lies within a given unit cell is:
1/8
If we cool a eutectoid composition steel (0.77% C) under near-equilibrium conditions, the resulting microstructure will be
100% pearlite
If we cool a eutectoid composition steel (0.77% C) under near-equilibrium conditions, the resulting microstructure will be:
100% pearlite.
Structures with stacked close-packed planes have____ nearest neighbor atoms (i.e. the coordination number)
12
The coordination number for a structure that contains close-packed planes is: A. 6 B. 8 C. 12 D. 14
12
In order to be considered as a true stainless steel, an iron-based metal must contain more than: A. .77% B. 12% nickel C. 12% chrome D. 12% silicone
12% chrome
In order to be considered as a true stainless steel, an iron-based metal must contain more than:
12% chromium
(Lead-Tin (Pb-Sn) diagram) -- The chemistry of the first solid to appear when 30% tin alloy is cooled under equilibrium conditions is
14% Sn
(Lead-Tin (Pb-Sn) diagram) -- The temperature of the eutectic reaction is closest to
183 C
The functionality of polymer reactants that form linear or chain-type polymers is:
2
The number of atoms or lattice points fully contained in a BCC unit cell is:
2
For the Ac-40%Bg alloy, the solidus temperature is
295
If a piece of equilibrium cooled 40% Bg alloy were heated from room temperature, melting would begin when the temperature reaches
295 C
A cast iron alloy contains 2.8% carbon, 1.8% silicon, 1% chromium and 1% nickel. Its carbon equivalent is:
3.4%
If a material contains 8 grains per square inch at 100X magnification, it would have an ASTM grain size number of:
4
The number of atoms or lattice points fully-contained in the FCC unit cell is:
4
The approximate amount of pearlite in a slow- cooled .4% C steel would be approximately: A. 25% B. 50% C. 75% D. 100%
50%
The approximate amount of primary ferrite in a .40% C steel (under equilibrium conditions) would be: A. 25% B. 50% C. 75% D. 100%
50%
A 9310 steel has been heat treated to achieve a Rockwell C hardness of 40. If the steel were changed to an 8640 alloy, and the heat treatment left the same, we would expect a final hardness to be Rockwell C ___. (use Jominy curves in text or on lecture slides)
53
(Lead-Tin (Pb-Sn) diagram) -- The composition of the liquid that is present when the 30% tin alloy is cooled under equilibrium conditions to 200 C is
55% Sn
(Lead-Tin (Pb-Sn) diagram) -- The highest strength material in the lead-tin system would be expected to occur at
61.9% Sn
For the Ac-40%Bg alloy, the composition of the solid that is present at 500 C is
70%
For the Ac-40%Bg alloy, the liquidus temperature is
700
The packing factor for structures involving stacked close-packed planes (highest possible) is:
74%
A flat plate of metal is cold-rolled from 1-inch thick to 1/2-inch and then further to 1/4-inch, with no increase in width. The total amount of cold work performed is:
75%
The amount of pearlite in a slow-cooled 0.6% C steel would be approximately:
75%
In any cubic lattice, corner atoms are shared by ___ unit cells.
8
In the BCC crystal structure, the coordination number is:
8
For the Ac-%Bg alloy, the composition of the first solid to appear upon cooling is
90% Bg
A shorthand notation for all cube edges in cubic crystals would be: A. <100> B. <110> C. <111> D. <123>
<100>
A shorthand notation for all face diagonals in cubic crystals would be:
<110>
The close-packed directions in FCC crystals have the Miller Indices form of: A. <100> B. <110> C. <111> D. <000>
<110>
The directions of atom-touching (close packed directions) in the FCC structure have the Miller Indices form of:
<110>
The directions of atom-touching (close packed directions) in the bodycentered cubic structure have the Miller Indices form of:
<111>
A slip system consists of:
A direction and a plane of possible dislocation movement
Primary ferrite forms when we cool between this temperature line and the A1.
A3
Primary ferrite forms when we cool between this temperature line and the A1. A. A1 B. A2 C. A3 D. Acm
A3
The stacking sequence for the HCP crystal structure is:
ABABAB
The stacking sequence for the FCC crystal structure is:
ABCABC
The stacking sequence of close-packed planes in the face-centered cubic (FCC) crystal structure is:
ABCABC
For aluminum alloys, the highest strength is achieved through: A. Grain size control B. Cold working C. Age hardening D. Solid solution strengthening
Age hardening
Which of the following is not an asset of cold working?
All materials can be strengthened (metals, ceramics, polymers & composites).
For the most effective dispersion strengthening, the dispersed second phase should be: A. Discontinuous B. Strong and hard C. Many small particles D. All of A, B and C. E. None of A, B and C
All of A, B and C
The crystal structures of ceramic materials are often quite complex because: A. Atoms of different sizes are in the same structure B. Covalent structures often have a limited number of nearest neighbors C. Charge neutrality must be maintained throughout ionic structures D. All of the above
All of the above
When welding metals, the once-molten-metal region (fusion zone) of a weld can experience which of the following problems? A. Shrinkage problems B. Gas porosity C. Columnar crystals D. All of the above
All of the above
Attractive properties for casting alloys include:
All of these
Diffusion is required for or useful in:
All of these
When a design engineer defines requirements, these requirements are: A. Mechanical properties B. Manufacturing requirements C. Geometric requirements D. All of these are design requirements
All of these are design requirements
At a given elevated temperature, diffusion of atoms would be easiest for atom movement:
Along free surfaces
The surface treatment known as carburizing a material, such as a gear, is an example of a(n): A. Altered surface chemistry B. Single chemistry - dual heat treatment
Altered surface chemistry
The corrosion resistance of aluminum and titanium alloys can be attributed to: A. Low chemical reactivity of the metal itself B. An adherent, protective oxide film
An adherent, protective oxide film
The "critical cooling rate" is the slowest cooling that will produce: A. An all martensite structure B. An all pearlite structure C. Retained austenite
An all martensite structure
A substitutional point defect is: A. An atom missing from a lattice point B. An atom of one species occupying a lattice point in a lattice of another species C. An atom that is inserted into a crystal at a location that is not a lattice point.
An atom of one species occupying a lattice point in a lattice of another species
The corrosion resistance of copper and nickel is: A. An inherent property of the metal B. Due to an adherent oxide
An inherent property of the metal
When the elastic-to-plastic transition is not distinct, we often define and agree on: A. A strain-hardening exponent B. The ultimate tensile strength C. An offset yield strength D. The breaking strength
An offset yield strength
The properties of cold worked components are usually: A. Anisotropic B. Isotropic
Anisotropic
Which of the following is NOT a correct statement about cold working? A. We can strengthen the material while producing the desired shape B. Anisotropy and residual stresses are always detrimental C. Dimensional tolerances and surface finish tent to be good D. Ductility, electrical conductivity, and corrosion resistance decrease
Anisotropy and residual stresses are always detrimental
Metals might be annealed to accomplish which of these? A. Increase ductility B. Improve conductivity C. Relieve residual stresses D. Any of these
Any of these
Which of the following is an alternate term for additive manufacturing?
Any of these
In Schmid's Law, τ = σ Cos λ Cos φ , the symbol σ is known as the:
Applied stress
When we solidify a pure metal, solidification occurs ___ and appears as a ___ on a cooling curve.
At a fixed temperature; horizontal hold
To cause a cold-worked material to recrystallize, we must expose it to elevated temperature. This is because the recrystallization process requires:
Atomic diffusion
In this isothermal heat treatment, austenite is transformed below the nose of the T-T-T diagram to produce bainite: A. Isothermal anneal B. Austempering
Austempering
The elevated temperature (FCC) form of iron that can contain up to 2.11% carbon in solid solution is called: A. Ferrite B. O-Ferrite C. Austenite D. Cementite
Austenite
Quench cracking is a distinct possibility when rapidly cooling steels because the cooling is non-uniform (surfaces cool faster than interiors) and: A. Austenite contracts when it transforms to martensite B. Austenite expands when it transforms to martensite
Austenite expands when it transforms to martensite
The term "degree of polymerization" describes the: A. Average number of mers per molecule B. Number of different types of mers in a polymer C. Number of places other units can attach to a mer
Average number of mers per molecule
The activation energy would be lower (diffusion is easier) for which of these?
BCC iron (68% PF)
The crystal structure of martensite: A. FCC B. BCC C. BCT-- a distorted BCC where T= tetragonal
BCT
The crystal structure of martensite is:
BCT -- a distorted BCC where T = tetragonal
the crystal structure of martensite is
BCT -- a distorted BCC where T = tetragonal
The microstructure that forms below the "nose", but above Ms in a eutectoid steel T-T-T diagram is: A. Pearlite B. Bainite C. Martensite
Bainite
Compared to materials with other crystal structures, materials with the HCP structure tend to:
Be brittle
This lightweight metal is unique in being lighter than aluminum, but stiffer than steel. Unfortunately it is also brittle in room temperature and the oxide is considered to be toxic. A. Nickel B. Beryllium C. Magnesium D. Titanium
Beryllium
This metal is lighter than aluminum, but stiffer than steel.
Beryllium
This metal is sometimes used for nuclear applications because it is relatively transparent to the movement of neutrons.
Beryllium
The density of titanium is: A. Higher than steel B. Between steel and aluminum C. Lower than aluminum
Between steel and aluminum
We can promote the process of solidification by: A. Cooling further below the melting temp B. Providing nucleating surfaces C. Both A and B D. Neither A nor B
Both A and B
This structural feature is unique to dispersion strengthening. A. Substitutional point defects B. Boundaries between two different phases C. Grain boundaries D. Dislocation multiplication
Boundaries between two different phases
Among the quenchants of brine, water, and oil, the fastest cooling would be expected in: A. Oil B. Water C. Brine (salt water)
Brine (salt water)
During quenching, the most rapid cooling occurs during the ___ stage. A. Vapor jacket B. Bubble formation & removal C. Conduction & convection
Bubble formation & removal
The "maps" that have been developed to streamline the comparison of selection criteria between materials are called:
Bubble or Ashby chart
The cooling conditions experienced by parts undergoing actual cooling are most accurately reflected in the: A. Equilibrium phase diagram B. T-T-T diagram C. C-T-T diagram
C-T-T diagram
List a disadvantage for threaded fasteners that was discussed in the TUDelft video "Comparing Threaded Fasteners and Rivets"
Can be Removed after installation
When a crystalline solid is heated to a high temperature, the atoms:
Can move about within the crystalline solid
The refractory metals usually have some form of protective coating. This coating is a : A. ceramic B. Polymer C. Titanium alloy D. Copper alloy
Ceramic
Materials in this family are hard or strong, offer good electrical and thermal insulation, and can be attractive for elevated temperature applications. Unfortunately, they are generally brittle. A. Metals B. Ceramics C. Polymers
Ceramics
Materials in this family have high melting temperatures, are typically hard and brittle, and have low thermal and electrical conductivity.
Ceramics
List an advantage for rivets that was discussed in the TUDelft video "Comparing Threaded Fasteners and Rivets"
Cheap and Forms Permanent Fastener After Installation
In this region of a casting, typically the first region to solidify, many small grains form due to rapid nucleation on the walls of the mold: A. Chill B. Columnar C. Equiaxed D. Heat affected
Chill
This region of casting results from the selective growth of already- existing, favorably-oriented grains: A. Chill B. Columnar C. Equiaxed D. Heat affected
Columnar
Useful shapes are generally created from crystalline ceramics by: A. Plastic deformation using rolling, forging and extrusion B. Melting and solidification C. Compaction of fine powders followed by sintering (pressing and firing)
Compaction of fine powders followed by sintering (pressing and firing)
Which of the following is NOT a correct statement regarding composite materials? A. Distinct interfaces are present between component materials B. The components can be metals, ceramics, polymers, or even natural materials C. Each component retains its identity, structure, and properties D. Composite materials can be easily separated and recycled
Composite materials can be easily separated and recycled
Tempered glass acquires its enhanced toughness or fracture resistance through: A. Compressive residual stresses B. A continuous metal matrix C. Weak interfaces between components D. A metastable phase that transforms
Compressive residual stresses
Two different types of monomers or reactants are required for this type of polymerization that involves the production of a small by-product molecule.
Condensation polymerization
The H-14 suffix in 3003-H14 provides information relating to: A. Purity B. Alloying elements C. Carbon content D. Condition (past processing history)
Condition (past processing history)
The dominant uses of copper and copper alloys utilize the properties of: A. Lightweight and corrosion resistance B. Strength and color C. Conductivity and corrosion resistance D. Elevated temperature strength and wear resistance
Conductivity and corrosion resistance
A martensitic steel is one that: A. Contains significant amounts of carbon and achieves much of its strength from phase transformation hardening B. Is the cheapest, and if it achieves most of its strength from solid solution strengthening C. Offers the greatest ductility and formability (because of its FCC crystal structure)
Contains significant amounts of carbon and achieves much of its strength from phase transformation hardening
Shrink voids can form during solidification because when a metal goes from liquid to solid, it generally: A. Contracts B. Expands
Contracts
The number of "nearest neighbor" atoms in a crystal structure is called the:
Coordination number
This metal has the best overall electrical and thermal conductivity, along with good formability and corrosion resistance:
Copper
In this type of bonding, the bonds are "directional" (wanting a set and limited number of nearest neighbors). The resulting materials have relatively low density. A. Metallic B. Ionic C. Covalent D. Vander Waals
Covalent
The bonding mechanism between the atoms along the spine of linear polymers is:
Covalent
In linear polymers, the bonding along the length of the fiber or chain is ____, but the bonding attraction between the molecular fibers or chains is ____. A. Ionic, covalent B. Covalent, ionic C. Covalent, vanderWaals D. VanderWaals, covalent
Covalent, VanderWaals
A stress-rupture diagram, including lines for various temperatures, is a compilation of data from multiple ___ tests. A. Tensile B. Impact C. Fatigue D. Creep E. Hardness
Creep
The stress required for a dislocation to move is called the:
Critical resolved shear stress
The properties of engineering metals are primarily dependent upon and controlled by the:
Crystal defects
The endurance limit is one measurement of a material's ability to endure: A. Cyclic loadings B. Impact loads C. Elevated temperatures D. Wear conditions
Cyclic loadings
When a precipitate grows to the point where it loses "coherency" and becomes a distinct second phase, the strength of the material: A. Increases B. Decreases C. Remains unchanged
Decreases
To be age hardenable, an alloy should display a phase diagram with: A. increasing solubility with decreasing temperature B. Decreasing solubility with decreasing temperature
Decreasing solubility with decreasing temperature
Deformation or ductility in a metal is the result of movement of this type of defect.
Dislocation
The strength of engineering metals is significantly lower than the theoretical strength (such as 30,000 psi and not 3 million). The defect responsible for this is called a(n).
Dislocation
The type of crystalline defect whose movement provides the plastic deformation observed in ductile metals is the: A. Vacancy B. Substitutional C. Dislocation D. Grain Boundary
Dislocation
The type of defect responsible for the increased strength obtained during strain hardening (deformation strengthening) is the:
Dislocation
Line imperfections in a crystalline solid are called:
Dislocations
The strength increase observed during strain hardening is primarily due to an enormous increase in the number or amount of: A. Substitutional atoms B. Dislocations C. Interstitial atoms D. Vacancies
Dislocations
When a material is heated to elevated temperature, the diffusing atoms will tend to:
Distribute uniformly throughout the host material
Which of the following is NOT a correct statement regarding magnesium?
Ductility and corrosion resistance are both good.
An adhesive example of this type of polymer would be flexible silicone bathtub caulk.
Elastomeric
Extremely large elastic deformations are possible with this type of polymer.
Elastomeric
The activation energy (the Q in the D= De^(-Q/RT)) is a measure of the: A. Number of atoms passing across a plane in a given time B. Energy required to cause an atom to move position within a crystal C. Distance an atom will move in a single jump
Energy required to cause an atom to move position within a crystal
Because the properties of this internal region of a casting are attractive, inoculation may be used to promote its formation or increase its size: A. Chill B. Columnar C. Equiaxed D. Heat affected
Equiaxed
(Hypothetical Phase Diagram) -- Reaction at 450 C
Eutectoid
In this reaction a solid separates to form a mixture of two new solid phases
Eutectoid
Which of the following reactions occurs entirely in the solid state
Eutectoid
Which of the following reactions occurs entirely in the solid state? A. Eutectic B. Eutectoid C. Peritectic D. Monotectic
Eutectoid
Upon cooling, iron changes from FCC to a BCC. Because of the relative packing factor efficiencies of these structures, iron will __ when it transforms from FCC to BCC. A. Contract B. Expand C. Remain unchanged
Expand
When iron cools from red-heat to room temperature, it changes from FCC to BCC. Because of this change and the different packing factors associated with these structures, iron ____ during this change.
Expands
Aluminum, copper, silver and gold are "soft, weak and extremely ductile". These properties are characteristic of metals with this crystal structure.
FCC
Because this structure has four non-parallel slip planes {111} with three slip directions in each for a total of 12 slip systems, it exhibits exceptional ductility. A. BCC B. FCC C. HCP
FCC
Cold work strengthening is highly effective for metals with this crystal structure:
FCC
Cold working is an effective means of strengthening materials with this crystal structure A. SC B. BCC C. FCC D. HCP
FCC
Materials with this structure are very ductile, since it has four different slip planes and three slip directions in each - for twelve slip systems.
FCC
Strain hardening is most effective (greatest increase in strength) in metals with which of these crystal structures?
FCC
In the FCC unit cell, the atoms are "touching" along the:
Face Diagonals
In the face-centered cubic (FCC) crystal structure, atoms touch along the: A. Cube edges B. Body diagonals C. Face diagonals
Face diagonals
A high-strength aerospace aluminum alloy has strength equivalent to a quenched-and-tempered medium carbon steel.
False
Adhesive bonding is an attractive means of joining materials that will be used at elevated temperature.
False
Friction Stir Welding can be used to join most metals
False
Friction Stir Welding is frequently used to join steel.
False
Good electrical and thermal conductivity is a characteristic or description of most polymeric materials.
False
Good mechanical properties at elevated temperature is a characteristic or description of most polymeric materials.
False
Good wear resistance is a characteristic or description of most polymeric materials.
False
Magnesium can be significantly strengthened by cold work.
False
Parallel line striations and "beach marks" that appear on fracture surfaces are characteristic of failure by this means: A. Tensile B. Impact C. Fatigue D. Creep
Fatigue
The room- temperature (BCC) form of iron that can only contain up to .02% carbon in solid solution is called: A. Ferrite B. O-Ferrite C. Austenite D. Cementite
Ferrite
In which of these metal joining techniques does the metal to be joined not melt?
Friction Stir Welding
Which of these process heat treatments produces the weakest, most ductile product for any carbon content steel? A. Process Anneal B. Full anneal C. Normalize D. Spheroidize
Full anneal
Which of the following is NOT a characteristic property of ceramic materials? A. Good corrosion resistance and chemical stability B. High melting temperature C. Hard and rigid, but brittle D. Good electrical and thermal conductivity
Good electrical and thermal conductivity
Which of the following is not an asset of aluminum?
Good elevated temperature strength
Which of the following is NOT an attractive asset of aluminum and aluminum alloys? A. Easy to fabricate B. Very ductile C. Good electrical and thermal activity D. Good strength at elevated temperature
Good strength at elevated temperature
Which of these crystalline defects is not classified as a point defect?
Grain Boundary
In a polycrystalline material, the surfaces that are created where the individual crystals meet are called:
Grain boundaries
Superplastic behavior is a result of which deformation mechanism? A. Dislocation multiplication B. Grain boundary sliding C. Cross-slip of dislocations D. Localized melting
Grain boundary sliding
During this stage of annealing, strength continues to drop, but there is little change in other properties. This stage is usually considered to be undesirable.
Grain growth
Which stage of annealing is usually considered to be undesirable?
Grain growth
Compacted graphite cast iron has a structure and properties that fall between is: A. Malleable and ductile B. Gray and ductile C. White and Malleable D. Gray and white
Gray and ductile
If we were to add 5% nickel to pure copper to produce a copper-5% nickel alloy, the ductility of the alloy would be ___ the strength of pure copper. A. Greater than B. The same as C. Less than
Greater than
Magnesium and zinc die castings (such as Hot Wheels cars), are characteristically brittle. This is because these metals have the ____ crystal structure.
HCP
Materials with this structure tend to be brittle because there is only one identifiable slip plane, and it may not be favorably oriented.
HCP
The crystal structure that contains close-packed planes stacked in the ABABAB sequence is: A. SC B. BCC C. FCC D. HCP
HCP
Zinc and magnesium are generally brittle at room temperature. This brittleness is a characteristic of the ___ crystal structure.
HCP
The Jominy test is used to evaluate the ____ of a steel. A. Ductility B. Hardness C. Hardenability
Hardenability
This type of test is the quickest and least expensive to conduct, and is frequently used as a quality control check during manufacturing operations.
Hardness
This type of test is the quickest and least expensive to conduct, and is frequently used as a quality control check during manufacturing operations. A. Tensile B. Impact C. Fatigue D. Creep E. Hardness
Hardness
Which of the following is NOT a correct statement regarding magnesium? A. Has a wide range of mechanical properties since it responds well to strengthening B. Has good machining characteristics, but the chips can burn C. Like aluminum, is poor in wear, creep and fatigue D. Has the HCP crystal structure and is characteristically brittle
Has a wide range of mechanical properties since it responds well to strengthening
Compared to materials with other structures, materials with the BCC structure tend to: A. Have greater strength B. Have greater ductility C. Be brittle
Have greater strength
The third and final step of a three-step age hardening heat treatment would be to: A. Heat to a temp between the liquidus and solidus B. Heat to the single phase region and hold to produce a homogeneous solid C. Heat the super saturated phase material to a temperature below the solvus where the second phase will precipitate
Heat the super saturated phase material to a temperature below the solvus where the second phase will precipitate
The initial first step of a three- step age hardening heat treatment would be to: A. Heat to a temp between the liquidus and solidus B. Heat to the single phase region and hold to produce a homogeneous solid C. Heat the super saturated phase material to a temperature below the solvus where the second phase will precipitate
Heat to the single phase region and hold to produce a homogeneous solid
All of the high-temperature refractory metals are:
Heavier than steel
Which of the following is a significant limitation to the use of copper and copper alloys? A. Poor formability B. Poor conductivity C. Heavier than steel D. Poor corrosion resistance
Heavier than steel
Which type of nucleation is promoted by adding impurity particles to the melt (inoculation)? A. Homogeneous B. Heterogeneous
Heterogeneous
Which type of nucleation is rarely observed during normal solidification? A. Homogeneous B. Heterogeneous
Homogeneous
If we increase the temperature, we would expect the diffusion coefficient to:
Increase
Increasing the length of the average chain would _______ the strength of a polymer.
Increase
Inducing "crystallization" during cooling would _______ the strength of a polymer.
Increase
Replacing hydrogen side atoms with chlorine would _______ the strength of a polymer.
Increase
As the temperature is increased in the range of atomic diffusion, we would expect the rate of atom movement to ___ with temperature. A. Increase linearly B. Decrease linearly C. Increase exponentially D. Decrease exponentially
Increase exponentially
As the temperature is increased in the range of atomic diffusion, we would expect the rate of atom movement to___ with temperature.
Increase exponentially
If we increase the temperature, the flux or the amount of atom movement will:
Increase exponentially
Plastically deforming of "Cold working" a thermoplastic polymer would: A. Increase the strength of the resulting polymer B. Decrease the strength of the resulting polymer C. The strength of the polymer does not depend on deformation
Increase the strength of the resulting polymer
Replacing hydrogen side atoms with chlorine to form a copolymer would: A. Increase the strength of the resulting polymer B. Decrease the strength of the resulting polymer C. The strength of the polymer does not depend on the side atoms
Increase the strength of the resulting polymer
During a creep test, we would expect the rupture time to decrease if we ___ the magnitude of loading or ___ the test temperature.
Increase, increase
As the carbon content of the steel increases, the strength and hardness of the resulting martensite: A. Increases B. Decreases
Increases
Adding crystalline imperfections to a metal lattice almost always ____ the strength and ___ the ductility.
Increases, decreases
Which of these composite joining methods requires a conductive composite or a susceptor between the composites to be joined?
Induction Welding
The key feature of the dispersion strengthening mechanism is:
Interfaces between the two solid phases
The activation energy would be lower (diffusion is easier) for which of these?
Interstitial carbon atom in iron
Carbon atoms are much smaller than iron atoms. We would expect carbon to move in iron by:
Interstitial diffusion
Since none of the crystal structures have 100% packing efficiency, smaller atoms may fit into the spaces between the host atoms. These locations and the atoms lying there are called:
Interstitials
Diffusion is more difficult in ____ bonded materials.
Ionic
This type of bonding requires two different types of atoms (an electron donor and an electron receiver).
Ionic
The bonding in ceramic materials is: A. Ionic and metallic B. Covalent and metallic C. Ionic and covalent D. Covalent and van derWaals
Ionic and covalent
If the size of nucleating solid is greater that the critical radius for a given temperature,____: A. It will remelt, ex return to liquid B. It will continue to grow into a larger solid C. It will divide and create additional nuclei
It will continue to grow into a larger solid
In Fick's First Law, J= -D(dc/dx), the resultant movement of atoms (flux) is represented by this term: A. J B. D C. dc D. dx
J
Dual-phase steels are quenched from a temp that is: A. Just above the A1 B. midway between the A3 and A1 C. Above the A3
Just above the A1
Plywood, safety glass, bimetallic strip and Alclad are all examples of this type of composite A. Laminar B. Particulate C. Fiber-reinforced
Laminar
Which of the following is a correct statement regarding cold work?
Large forces are required
A material with an ASTM grain size of 4 would have ___ crystals compared to one of ASTM 8, and would also be ___.
Larger, weaker
A material with an ASTM grain size of 8 would have ___ crystals compared to one of ASTM 2, and would also be ___.
Larger, weaker
Compared to a metal with an ASTM grain size of 6, a material with a grain size number of 4 would have _____ crystals and would be _____.
Larger, weaker
Which of these metal joining processes would you expect to be the fastest?
Laser Welding
The thermodynamic term for the amount of heat energy released when liquid cools to a solid is: A. Specific Heat B. Superheat C. Latent heat of fusion D. Undercooling
Latent heat of fusion
A collection of ordered points in space is called a _____.
Lattice
In a crystalline lattice, the distance between adjacent lattice points (in a specified direction) is the: A. Miller index B. Lattice parameter C. Packing factor D. Coordination Number
Lattice parameter
The aspect ratio of a reinforcing fiber is the ratio of its: A. Strength to stiffness B. Strength to density C. Length to diameter D. Density to that of the matrix
Length to diameter
In fiber-reinforced composites, the term "aspect ratio" refers to the ratio of:
Length to diameter of the fibers
If we were to add 5% nickel to pure copper to produce a copper-5% nickel alloy, the ductility of the alloy would be ___ the ductility of pure copper. A. Greater than B. The same as C. Less than
Less than
Compared to aluminum, magnesium alloys are: A. Stronger B. Lighter C. More ductile D. More corrosion resistant
Lighter
Carbon is an interstitial atom when dissolved in iron. Because it is an interstitial, the solubility of carbon would definitely be: A. Zero B. Limited C. Unlimited
Limited
The temperature below which a material begins to solidify upon cooling is called the: A. Freezing range B. Liquidus C. Solidus D. Solvus
Liquidus
The designation system for this metal consists of two letters followed two or three numbers, such as AZ61 or AM100.
Magnesium
This metal can be very difficult to fabricate. It is brittle at room temperature; machining chips can burn: and molten metal must be kept under protective atmospheres
Magnesium
This type of cast iron, which is extremely hard and used almost exclusively for its outstanding wear resistance, has all of its high carbon in the form of Fe3C. A. Gray B. White C. Malleable D. Ductile E. Compacted graphite
Malleable
For a given steel, which of the following structures has the highest strength and hardness?
Martensite
The true equilibrium form of carbon in iron-carbon alloys is: A. Cementite B. Austenite C. Martensite D. Graphite
Martensite
Which of the following structures is NOT a mixture of ferrite and cementite? A. Pearlite B. Bainite C. Martensite D. Tempered martensite
Martensite
Which of the following structures is not a mixture of ferrite and cementite?
Martensite
Met 2110 focuses on which step in the manufacturing sequence? A.Material Selection B. Process selection C. Manufacture or fabrication D. Evaluation
Material Selection
The first step in the activity sequence for manufactured products is
Material selection
Residual stresses produced by cold working: A. Are always detrimental B. May be advantageous or detrimental C. Are always advantageous
May be advantageous or detrimental
Because of the type of bond, diffusion would be easiest to activate in materials with ___ bonding. A. Ionic B. Covalent C. Metallic
Metallic
Because the electrons in this type of bonding are not captive to either atoms or locations, but are free to wander throughout the structure, electrical and thermal conductivities are good, and the materials are often ductile. A. Metallic B. Ionic C. Covalent D. Vander Waals
Metallic
Dislocations move most easily and impart ductility in materials with this type of bonding:
Metallic
In general, we would expect diffusion to be easiest in materials with ___ bonding.
Metallic
Materials with this type of bonding can exhibit both high strength and high ductility.
Metallic
The valence electrons in this type of bonding are no longer associated with a particular atom or a specific location, but are free to wander throughout the entire structure
Metallic
The valence electrons in this type of bonding are no longer associated with a particular atom or a specific location, but are free to wander throughout the entire structure.
Metallic
Materials in this family often exhibit good strength and good ductility. They are also good electrical and thermal conductors. A. Metals B. Ceramics C. Polymers
Metals
The activation energy would be lower (diffusion is easier) for which of these?
Metals
This class of materials typically has high ductility, and a high electrical and thermal conductivity.
Metals
The stiffness or rigidity of a material can be evaluated by this tensile test property:
Modulus of Elasticity
The superalloy metals are based on which two metals? A. Nickel and cobalt B. TItanium and copper C. Tungsten and molybdenum D. Beryllium and magnesium
Nickel and cobalt
Which of these process heat treatments cools steel in air during the transformation process? A. Process anneal B. Full Anneal C. Normalize D. Spherodize
Normalize
Carbon atoms are much smaller than iron atoms. We would expect the carbon atoms to: A. Occupy interstitial sites B. Occupy substitutional sites. C. Lie on grain boundaries
Occupy interstitial sites
Copper and zinc are similar-size atoms. If zinc atoms are added to copper, they would be expected to:
Occupy substitutional sites
An austenitic stainless steel is one that: A. Contains significant amounts of carbon and achieves much of its strength from phase transformation hardening B. Is the cheapest, and if it achieves most of its strength from solid solution strengthening C. Offers the greatest ductility and formability (because of its FCC crystal structure)
Offers the greatest ductility and formability (because of its FCC crystal structure)
Since it would be the least tightly bonded, the lowest temperature would be required to activate movement of an atom lying: A. On a free surface B. Along a grain boundary C. Within a crystal
On a free surface
In order to move a dislocation, we must
Only break the bonds along a row or line of atoms
In order to move a dislocation, we must A. Break all the bonds over an entire surface or plane of atoms B. Only break the bonds along a row or line of atoms C. Only break the bonds to a single or individual atom
Only break the bonds along a row or line of atoms
When we solidify a metal alloy, solidification occurs ___ and appears as a ___ on a cooling curve.
Over a freezing range; slope change
If an age-hardened aluminum-copper alloy is reheated to diffusion temperatures, the result will likely be: A. Overaging and an increase in strength B. Overaging and a loss of strength C. A decrease in ductility
Overaging and a loss of strength
From tensile test data, this property is computed as (Ao - Af)/Ao x 100%
Percent reduction in area
(Hypothetical Phase Diagram) -- Reaction at 1150 C
Peritectic
(Hypothetical Phase Diagram) -- Reaction at 300 C
Peritectoid
Which of the following reactions is most sluggish and most likely to result in a nonequilibrium final structure
Peritectoid
For an edge dislocation, the Burger's vector is ___ to the dislocation line:
Perpendicular
Ceramic materials excel when: A. Mechanical properties dominate the selection process B. Physical properties dominate the selection process
Physical properties dominate the selection process
If the liquid ahead of a growing solid has a temp higher than the melting point, growth into the liquid will be: A. Dendritic growth B. Planar growth
Planar growth
Materials that can exist in more than one crystal structure (depending upon the conditions of temperature and pressure) are called:
Polymorphic
Which of the following is not a limitation of magnesium and magnesium alloys?
Poor machinability
Which of the following is NOT a limitation of aluminum? A. Poor thermal conductivity B. Poor wear resistance C. Low stiffness D. Poor in fatigue
Poor thermal conductivity
A material with lots of little crystals would be expected to have ___ electrical conductivity than the same metal with larger crystals.
Poorer
Which of the following techniques is used to impart enhanced rigidity and dimensional stability to the rubbery elastomers? A. Produce longer chains B. Promote cross-linking C. Initiate branching D. Cold work (deform) the polymer
Promote cross- linking
All of the mechanical assessment tests (tensile, impact, fatigue, hardness) relate to this aspect of materials engineering.
Properties
In a fiber-reinforced composite, we ask the matrix material to do all of the following EXCEPT:
Provide strength and stiffness
In a fiber-reinforced composite, we ask the matrix material to do all of the following EXCEPT: A. Provide strength and stiffness B. Provide ductility and toughness C. Support the fibers D. Provide desired electrical or thermal conductivity
Provide strength and stiffness
We can promote the nucleation of a solid by:
Providing existing surface,Decreasing the liquid temperature
Which of the following is NOT a standard condition for the tensile test? A. Rapid rate of loading B. Diameter of .505 inches C. Room Temp D. Gage length of 2 inches
Rapid rate of loading
During which stage of annealing are there no "optically-observable" changes to the structure, but some properties do change?
Recovery
During which stage of annealing do dislocations move, but do not decrease in amount.
Recovery
The stage of annealing where the residual stresses from cold working are eliminated, but the strengthening remains is: A. Recovery B. Recrystallization C. Grain Growth
Recovery
During this stage of annealing, new grains nucleate and grow, ductility is restored, and strength drops significantly.
Recrystallization
During which stage of annealing are new grains nucleated and grown?
Recrystallization
During which stage of annealing are the effects of strain hardening removed and ductility restored?
Recrystallization
During which stage of annealing are the number or density of dislocations decreased dramatically?
Recrystallization
The stage of annealing where the effects of strain hardening are removed, and ductility is restored is: A. Recovery B. Recrystallization C. Grain Growth
Recrystallization
The stage of annealing where the number of dislocations decreases significantly is: A. Recovery B. Recrystallization C. Grain Growth
Recrystallization
During hot working:
Recrystallization continually removes the effects of deformation
The use of advanced ceramics is most limited by the inability to: A. Control material purity B. Control sintering time and temperature C. Reduce flaw size
Reduce flaw size
All members of this group have the BCC structure and are heavier than steel
Refractory metals
In order for this material to function at extremely high temperatures (approaching 3000ºF), protective coatings are required.
Refractory metals
Members of this group include tungsten, tantalum and molybdenum.
Refractory metals
If the temperature is increased, the value of the activation energy, Q, will:
Remain unchanged
Which of these composite joining methods requires a wire mesh to be embedded between the composites to be joined?
Resistance Welding
In Schmid's Law, τ = σ Cos λ Cos φ , the symbol τ is known as the:
Resolved shear stress
Which mechanical fastening method was predominantly utilized in applications experiencing a shear loading in the TUDelft video "Introduction to the Types of Mechanically Fastened Joints "
Rivets
Which mechanical fastening method would be preferred in applications experiencing a shear loading?
Rivets
Metallic-bonded materials prefer crystal structures with dense packing and a large number of nearest neighbors. The LEAST attractive structure is ___ since it has only ___ neighbors. A. SC -- 6 B. BCC -- 8 C. SC -- 8 D. BCC -- 6
SC -- 6
GE Aviation is investigating which composite material for applications inside jet engines?
SiC/SiC CMCs
For an edge dislocation, the dislocation line and Burger's vector combine to define a:
Slip plane
A material with a ASTM grain size of 8 would have __ crystals compared to one of ASTM 4. A. Smaller B. The same size C. Larger
Smaller
Increasing the cooling rate of a eutectic material will produce a structure with ___ interlamellar spacing (or layer thickness) and ___ strength. A. Smaller, higher B. Smaller, lower C. Larger, lower D. Larger, higher
Smaller, higher
Ideally, we would like the matrix of an age hardenable alloy to be: A. Hard and brittle B. Soft and ductile
Soft and ductile
Which of the following would NOT be desirable if we want good dispersion strengthening?
Soft, ductile precipitates in a hard matrix
The temperature at which a material is fully solidified is called the: A. Freezing range B. Liquidus C. Solidus D. Solvus
Solidus
The temperature below which a material is fully solidified is called the:
Solidus
Austenitizing is similar to this step in the age hardening sequence. Aging
Solution treatment
Austenitizing of steel is similar to this step in the age hardening sequence.
Solution treatment
Steel A has a flat hardenability curve and a maximum hardness of Rockwell C 35. Steel B has a hardenability curve that drops off quickly as Jd increases, but a maximum hardness of Rockwell C 65. The steel with the highest alloy content would be:
Steel A
Zinc atoms and copper atoms are approximately the same size. If a zinc atom occupies a lattice point in a crystal of nearly pure copper, the "defect" is called a(n):
Substitutional
Solid solution strengthening can be obtained through the addition of:
Substitutional or interstitial point defects
This type of crystalline defect is responsible for solid solution strengthening: A. Substitutional or interstitial point defects B. Grain boundaries C. Dislocations
Substitutional or interstitial point defects
Nickel and cobalt form the basis of this group.
Superalloys
Which of the following is not a true statement about hot working?
Surface finish and dimensional precision are good
Which of these fusion welding techniques would be best to join aluminum or titanium?
TIG Welding
Which of these joining techniques would not be used to join composite materials?
TIG Welding
Which of the following is not a correct statement regarding cold work?
The amount of deformation is essentially unlimited
In a two-phase region of an equilibrium phase diagram, the lever law can be used to compute: A. The time required to solidify B. The yield strength of the alloy C. The chemistry of each of the phases D. The amounts of each of the phases
The amounts of each of the phases
The anisotropy and residual stresses produced by cold working:
The anisotropy and residual stresses produced by cold working:
In Fick's First Law, J = -D dc/dx, the term "D" represents:
The diffusion coefficient
In Fick's First Law, J = -D (dc/dx), the term "J" represents:
The flux of atoms (# crossing an area in a given time)
One advantage fo additive manufacturing is the ability to optimize the components. This optimization is possible largely because:
The geometries of the AM component are not possible with conventional casting or machining techniques
Which of the following is NOT an attractive feature of adhesive bonding? A. The joints offer good strength at elevated temperatures (in excess of 500F) B. All materials and combinations can be joined C. The adhesive can provide noise and vibration damping D. Adhesives are light in weight
The joints offer good strength at elevated temperatures (in excess of 500F)
During hot working, the material is deformed at which temperatures? A. The melting temp. B. Room temp. C. The recrystallization temp.
The recrystallization temp
Plastic deformation commences when: A. The resolved shear stress equals the critical resolved shear stress B. The applied stress equals the critical resolved shear stress
The resolved shear stress equals the critical resolved shear stress
If one steel alloy has a flat hardenability curve and a maximum hardness of Rockwell C 35 and another steel alloy has a hardenability curve that drops off quickly as Jd Increases, but a maximum hardness of Rockwell C 65, which steel alloy has the highest carbon content? A. The steel with the flat hardenability curve B. The steel with the steep hardenability curve C. The steel with hardness of Rockwell C 35 D. The steel with hardness of Rockwell C 65
The steel with the hardness of Rockwell C 65
The Rule of Mixtures predicts properties based on: A. The size, shape and distribution of the components B. The volume fractions of the component materials C. The orientation of the component materials
The volume fractions of the component materials
This NDT technique uses infrared radiation for inspections
Thermographic Imaging
An adhesive example of this type of polymer would be hot-melt glue
Thermoplastic
An adhesive example of this type of polymer would be hot-melt glue.
Thermoplastic
Extremely large plastic deformations are possible with this type of polymer.
Thermoplastic
In this type of polymer, heating softens, cooling hardens, and the cycle can be repeated.
Thermoplastic
These polymers are the most easily recycled variety.
Thermoplastic
Which of these composite materials is most easily joined by welding?
Thermoplastic
The most easily recyclable polymers are almost always: A. Thermoplastics B. Thermosets C. Elastomers
Thermoplastics
Polymers of this type tend to have the highest strength and highest rigidity. Two-part epoxy is an example: A. Thermoplastic B. Thermoset C. Elastomer
Thermoset
An adhesive example of this type of polymer would be two-part epoxy.
Thermosetting
The highest rigidity is found in this type of polymer.
Thermosetting
The highest strength polymers would most likely be of this type.
Thermosetting
Composites for outer skin or structural aircraft application (non-jet engine) are typically carbon fibers in what type of matrix
Thermosetting Polymer or Thermoplastic
This is the only lightweight metal that is also considered to be an "elevated temperature" material, retaining useful strength up through 500C or 900F A. Aluminum B. Beryllium C. Magnesium D. Titanium
Titanium
This metal can offer strength comparable to heat-treated medium-carbon steel at a little more than half the weight of steel, and is often found in aerospace applications. A. Aluminum B. Beryllium C. Magnesium D. Titanium
Titanium
Which of the following is a correct statement regarding the joining of cold worked material?
To retain mechanical properties, cold worked materials should only be joined by low temperature joining methods.
Engineering strain is defined as: A. applied load/ original area B. Applied load/ actual area C. Total stretch/ original length D. The slope in the elastic region
Total stretch/ original length
Adhesive bonding is an attractive means of joining dissimilar materials.
True
Adhesive joints often compensate for their lower strength by increasing the area of the bond.
True
Brittleness is a property that is characteristic or descriptive of most ceramic materials
True
Can have integral color is a characteristic or description of most polymeric materials.
True
Good corrosion resistance is a characteristic or description of most polymeric materials.
True
Good elevated temperature creep resistance is a property that is characteristic or descriptive of most ceramic materials.
True
High hardness is a property that is characteristic or descriptive of most ceramic materials
True
High melting temperature is a property that is characteristic or descriptive of most ceramic materials.
True
Light weight is a characteristic or description of most polymeric materials.
True
Low thermal expansion is a property that is characteristic or descriptive of most ceramic materials
True
The corrosion resistance of titanium is due to an adherent oxide, much like aluminum.
True
When magnesium is the material of choice, it is almost always for weight reduction.
True
Which of the following is considered a refractory metal? A. Tungsten B. Magnesium C. Aluminum D. Nickel
Tungsten
Which of the following is considered a refractory metal? A. Tungsten B. Magnesium C. Aluminum D. Nickel
Tungsten
Linear or chain-type polymers form when the reacting mers have a functionality of: A. One B. Two C. Three or more D. Any of these
Two
The smallest volume of a lattice that retains all of its characteristics is called the:
Unit Cell
Dispersion-strengthened particulate composites are generally formed to extend or enhance the: A. Useful temperature range of a material B. Material toughness C. Material's ductility D. Material rigidity
Useful temperature range of a material
The defect that occurs when an atom is missing from a lattice point is called a(n):
Vacancy
The two most common mechanisms for diffusion are:
Vacancy and Interstitial
The two most common mechanisms for atom movement (diffusion) are: A. Vacancy and ring B. Vacancy and interstitial C. Ring and interstitial D. Dislocation and grain boundary
Vacancy and interstitial
Zinc atoms are about the same size as copper atoms. We would expect zinc atoms to move in copper by:
Vacancy diffusion
All of the bonding electrons are tied up within molecules in this type of bonding. If the charge is not distributed uniformly within the molecules, a weak electrostatic attraction can occur between the polarized molecules. Its effects are often significant in polymeric materials. A. Metallic B. Ionic C. Covalent D. Vander Waals
Vander Waals
In this weakest type of bonding, all of the electrons are tied up within discrete molecules. If the charge is not distributed uniformly within the molecules, a weak electrostatic attraction can occur between the various polarized regions.
VanderWaals
This type of bonding is considered the weakest of the four types listed below.
VanderWaals
This NDT technique sometimes employs an instrument called a borescope
Visual Inspection
This is the oldest NDT technique.
Visual Inspection
When fabricating products from thermoplastic polymers, production may be slowed because we must: A. Wait for the polymer to cool in the mold before it can be ejected. B. Provide time for the resin to cure in the mold before ejection C. Alloy time for the material to sufficiently cross-link
Wait for the polymer to cool in the mold before it can be ejected
A piece of pure copper has an ASTM grain size of 8 and a yield strength of 45,000 psi. If it is heated to a temperature where diffusion can occur and held for an extended period of time, we would expect the resulting material to be ___ and have ___ grains.
Weaker, larger
For diffusion processes, the activation energy, Q, is a measure of:
What is required to cause an atom to move from one location to another
This type of cast iron, which is extremely hard and used almost exclusively for its outstanding wear resistance, has all of its high carbon in the form of Fe3C. A. Gray B. White C. Malleable D. Ductile E. Compacted graphite
White
An aluminum alloy has the designation 3003-H14. This alloy would be a: A. Wrought alloy B. Casting alloy
Wrought alloy
What is the difference between wrought and cast alloys? A. Wrought is single-phase, cast is multi-phase B. Wrought is heat-treated, cast are not-heat-treated C. Wrought is shaped as a solid, cast is shaped as a liquid D. Wrought is strengthened by age hardening, cast is cold worked
Wrought is shaped as a solid, cast is shaped as a liquid
A stress-rupture diagram is a compilation of results from a number of ___ tests.
Yield Point or yield strength
The first signs of permanent or plastic deformation are most closely associated with this value on a tensile test curve:
Yield point
The first signs of permanent or plastic deformation are most closely associated with this value on a tensile test curve: A. Yield point B. Tensile strength C. Breaking strength
Yield point
From the chart below, which material would you choose if you needed a strength of at least 100MPa and a density greater than 5000kg/m3?
Zinc Alloys
A brittle second phase precipitate can make the entire material brittle if it forms as
a continuous film that wets grain boundaries
The aluminum designation system identifies metal chemistry. An aluminum alloy with a four-digit designation would be considered to be:
a wrought alloy.
The corrosion protection in galvanized steel is a result of:
a zinc coating, which is anodic to iron
Solution treatment is performed by heating material to a temperature that is:
above the solvus
Additives to an electrolyte which are preferentially adsorbed at the anode or cathode to provide protection against corrosion are called:
adding an inhibitor
The process of adding components to an electrolyte which are preferentially adsorbed at the anode or cathode to provide protection against corrosion are called:
adding an inhibitor
A "phase" is characterized by
all of these
Which property is necessary for the coatings applied to refractory metals?
all of these
Carburizing a material, such as a gear, is an example of a(n) ___ surface treatment.
altered surface chemistry
In the color anodizing process, the material being colored is:
aluminum oxide.
If we increase the amount of sulfur when "vulcanizing" elastomeric rubber, the product becomes stronger and more rigid. This is because of the increased:
amount of cross-linking
Cold worked components usually have ___ properties.
anisotropic
Laminar composites are always:
anisotropic
Corrosion in an electrochemical cell occurs at the:
anode
The portion of a metal part in contact with the lowest oxygen electrolyte will act as the:
anode
Once a specific material has been selected for a design, which of these might deter the use of that material, and cause you to reconsider?
any of these
The matrix for a fiber-reinforced composite can be:
any of these materials
If we wanted to estimate the properties that would be obtained during a normalizing heat treatment, we could evaluate the properties obtained:
at the opposite end of the Jominy specimen (far removed from the quenched end).
In this isothermal transformation treatment, austenite is transformed below the nose of the T-T-T diagram to produce bainite:
austempering
Which of the following heat treatments would result in the highest strength product? : [hint: consider the resulting microstructures!]
austempering
In this isothermal transformation treatment of steel, austenite is transformed below the nose of the T-T-T diagram to produce bainite:
austempering.
The elevated-temperature (FCC) form of iron that can contain up to 2.11% carbon in solid solution is called:
austenite
Quench cracking is a distinct possibility when rapidly cooling steels because the cooling is nonuniform (surfaces cool faster than interiors) and:
austenite expands when it transforms
The family of stainless steels that offers the greatest ductility and formability (because of its FCC crystal structure) is:
austenitic
This type of stainless steel can be easily identified and separated from the other types since it is not strongly attracted to a magnet.
austenitic
The "degree of polymerization" refers to the:
average number of mers per molecule.
The isothermal transformation product that forms below the "nose", but above Ms of the TTT diagram is:
bainite
If the Ac-40%Bg alloy were slowly reheated, liquid would begin to form at a temperature
below 300 C
Artificial aging is performed by heating a material to a temperature that is:
below the solvus
Dual-phase steels are quenched from a temperature that is:
between the A3 and A1
Very large and reproducible dimensional changes are produced by temperature changes in:
bimetallics
During cold working, energy is stored in the deformed metal in the form of:
both of the above
The structural feature that is unique to dispersion hardening is
boundaries between two different phases
Among the quenchants of brine, water, and oil, the fastest cooling would be expected in a ___ quench.
brine (salt water)
During quenching, the most rapid cooling occurs during the ___ stage.
bubble formation and removal
The primary or pro-eutectoid phase that forms when we cool between the Acm and A1 temperatures is:
cementite
For a given steel, the weakest structure would be
coarse pearlite
For a given steel, the weakest structure would be:
coarse pearlite
In this region in a casting anisotropic properties are always exhibited
columnar
The lease desirable properties in a casting are found in this region
columnar
This region in a casting results from the selective growth of already existing favorably oriented grains
columnar
If two sheets of pure nickel are fastened together by a nickel bolt and nut, and corrosion occurs in the crevice between the two sheets, it is probably due to a:
composition cell
If an annealed steel bar partially submerged in water corrodes just beneath the waterline, then the corrosion is probably due to a:
concentration cell
The suffix (the letter or letter and number that appear after the hyphen) in the aluminum designation system designates the material:
condition (past processing history).
The primary uses of copper are related to its:
conductivity and corrosion resistance.
Copper excels over other metals we have discussed in which property?
conductivity.
Shrink voids can form during solidification because when a metal goes from liquid to solid, it generally
contracts
The second step in a three-step age hardening heat treatment would be to:
cool the material rapidly from the single phase alpha region (quench) to produce a supersaturated solid solution
The equilibrium structure in ceramic materials (lowest energy) would be:
crystalline
If we drop the temperature further below the melting temperature (undercool) the size of the critical radius will
decrease
Increasing the amount of initiator or activator in an addition polymerization reaction will ___ the length of the chains and ___ the strength of the resulting polymer.
decrease, decrease
If we increase the cooling rate through the eutectoid reaction, the interlamellar spacing will ___ and the strength of the pearlite will ____.
decrease, increase
When a precipitate grows to the point where it loses "coherency" and becomes a distinct second phase, the strength of the material:
decreases
According to the materials selection video we watched from TU Delft, which of these steps comes first in the materials selection process?
determine the failure modes of the component
The increase in strength observed during cold work or strain hardening is primarily due to a vast increase in the number or amount of:
dislocations
A composite formed of a metal matrix containing small oxide particles that interfere with dislocation movement would be an example of:
dispersion strengthened composite
Carbon fibers are usually produced by:
driving off hydrogen from precursor polymer fibers
Properties equivalent to steel (strength, ductility and fracture resistance) are observed in this type of iron where smooth-surface graphite spheres form directly upon solidification.
ductile
if we increase the tempering temperature, we would expect an increase in
ductility
For in-space applications, the best choice for an additive manufacturing process would be:
e-beam plus wire feed
Beryllium is unique among the engineering metals because of its extremely high:
elastic modulus.
Corrosion in an electrochemical cell occurs at the location where
electrons leave the material
Corrosion in an electrochemical cell occurs at the location where:
electrons leave the material
Because of its FCC crystal structure, copper and copper alloys have
excellent formability.
The two phases in a "dual-phase" steel are:
ferrite and martensite
This family of stainless steel is the cheapest, and it achieves most of its strength from solid solution strengthening.
ferritic
The difference between the liquidus and solidus is called the
freezing range
In this heat treatment of steel, the resulting structure typically contains coarse pearlite:
full anneal
This heat treatment of steel produces the weakest, most ductile product for any carbon content steel:
full anneal
During the thermal arrest portion of a cooling curve, the material is
going from liquid to solid
In most age hardenable alloys, the precipitate is:
hard and brittle
Intermetallic compounds are usually:
hard and brittle
To be age hardenable, an alloy should be precipitates that are: A. Hard, brittle and incoherent B. Hard, brittle and coherent C. Soft, ductile and incoherent D. Soft, ductile and coherent
hard, brittle and coherent
The Jominy test is used to evaluate the ___ of a steel.
hardenability
Increasing the carbon content of a steel tends to increase ___. Increasing the alloy content increases ___.
hardness, hardenability
The third and final step of a three-step age hardening heat treatment would be to:
heat the supersaturated α phase material to a temperature below the solvus where the second phase will precipitate.
Consider the three-step heat treatment to age harden an aluminum- 4%cu alloy. Beginning with room temperature material, the first step would be:
heat tot he single phase alpha region and hold to produce a homogenous solid
The highest strength aluminum alloys are:
heat-treatable.
Besides its high temperature properties, tungsten is also:
heavier than lead.
Copper and copper alloys are:
heavier than steel.
Inoculation is a means of promoting ____ nucleation
heterogeneous
Because of retained austenite problems, a below-zero cooling operation would be most needed when quenching a ___ steel.
high carbon, plain carbon
Which of the following is NOT a characteristic of gray cast iron?
high fracture resistance
Because alloy elements retard tempering, the maximum operating temperature for alloy steels is ___ than for plain carbon steels.
higher
This type of nucleation is rarely obvserved during normal solidification
homogeneous
At least up to some point, increasing the volume fraction of fibers in a fiber- reinforced composite will:
increase the strength
As the carbon content of the steel increases, the strength and hardness of martensite
increases
As we cool between Ms and Mf, the martensite
increases in amount
Increasing the aspect ratio of whiskers
increases the strength of fiber-reinforced composites
The strength of fiber reinforced composites is increased by
increasing the volume fraction of fibers
Ceramic materials have ___ atomic bonding
ionic or covalent
In this isothermal transformation treatment, austenite is transformed to pearlite above the nose of the T-T-T diagram:
isothermal anneal
In this isothermal transformation treatment, austenite is transformed to pearlite above the nose of the T-T-T diagram:
isothermal anneal.
Because of their geometries, the properties of ___ composites are always anisotropic.
laminar composite
Clad coinage, such as U.S. dimes and quarters, are examples of:
laminar composite
Producing a material whose surface is corrosion resistant or wear resistant, while keeping the material relatively inexpensive is one example of an application for:
laminar composites
For elevated temperature creep resistance, a crystalline ceramic should have ___ crystals.
large
Which of the following configurations will have the slowest corrosion rate?
large anode area, small cathode area
Boeing utilizes an additive process they call "Laser Powder bed Fusion (LPBF), also known as Selective Laser Melting (SLM). This process results in manufactured components with:
large residual stresses, which must be relieved after the build
The thermodynamic term for the amount of heat energy released when liquid goes to solid is
latent heat of fusion
Heterogeneous nucleation requires ____ undercooling than homogeneous nucleation
less
If we were to add 5% nickel to pure copper to produce copper 5% nickel alloy, the resulting alloy would be ____ and ____ than copper.
less ductile
If we were to age harden the Al - 4%Cu alloy at 350°C, we would expect the maximum strength to be __ the maximum strength attainable with a 300°C aging temperature
less than
If we were to age harden the Al - 4%Cu alloy at 350°C, we would expect the time to achieve maximum strength to be ___ compared to the time to attain maximum strength at 300°C.
less than
Carbon is an interstitial atom when dissolved in iron. Because it is an interstitial the solubility of carbon in iron would definitely be
limited
For the Ac-40%Bg alloy, the stable phase(s) at 500 C are
liquid + alpha
Gas solubility is greater in ___ than it is in ___ material of the same chemistry
liquid, solid
The temperature at which a material begins to solidify upon cooling is called the
liquidus
This type of cast iron contains graphite "clumps" or "clusters" that form during a heat treatment.
malleable
The highest-strength steel would likely be a member of this group:
maraging
For a given steel, which of the following structures has the highest strength and hardness
martensite
Which of the following structures is not a mixture of ferrite and cementite?
martensite
This type of stainless can contain significant amounts of carbon and achieves much of its strength from phase transformation hardening.
martensitic
In a fiber-reinforced composite material, the ductility and toughness are provided by the:
matrix material
Anisotropy and the residual stresses produced by cold working
may be advantageous or detrimental.
From the chart below, which material would you choose if you needed a strength of at least 100MPa and a density less than 500kg/m3?
none of these
(Hypothetical Phase Diagram) -- Mu Phase (u)
nonstoichiometric intermetallic
In this heat treatment of steel, the resulting structure typically contains fine pearlite:
normalize
This heat treatment of steel cools material in still air during the transformation process:
normalize
If an age-hardened aluminum-copper alloy is reheated to diffusion temperatures, the result will likely be:
overaging and a loss of strength
The strength and stiffness of a directional fiber-reinforced composite will be highest:
parallel to the fibers
Because of their geometries, the properties of ___ composites are always isotropic.
particulate composite
Cemented carbides, or cermets, are a type of:
particulate composite
We would expect to find the most isotropic behavior in:
particulate composites
A lamellar structure of alternating layers of ferrite and cementite is a description of:
pearlite
Equilibrium cooling of a 0.77%C steel will produce a structure of 100% ___
pearlite
Equilibrium cooling of a 0.77%C steel will produce a structure of 100% ___.
pearlite
The isothermal transformation product that forms below A1, but above the "nose" of the TTT diagram is:
pearlite
The lamellar or layered structure, consisting of alternating plates of ferrite and cementite, is called:
pearlite
The lamellar or layered structure, consisting of alternating plates of ferrite and cementite, is called:
pearlite.
A hybrid additive manufacturing system combines:
powder fed laser deposition with CNC milling
(Lead-Tin (Pb-Sn) diagram) -- If a 30% tin alloy were equilibrium cooled to room temperature, we would expect to find a structure of
primary alpha plus eutectic
If we slow cool a hypoeutectoid steel (such as 0.4% C), the microstructure will contain:
primary ferrite plus pearlite
This heat treatment of steel is used to restore ductility to cold-worked low carbon steels by simply inducing recrystallization of the ferrite:
process anneal
Very light weight yet high stiffness can be obtained by:
producing aluminum honeycomb panels
When welding steel, there is great concern regarding the heat-affected zone. This region can:
reaustenitize and produce a new structure upon cooling, over-temper and further soften or weaken(both a and b)
If the size of an "embryo" is smaller than the critical radius, it will
remelt (revert back to a liquid)
Martempering or marquenching is a heat treatment designed to reduce:
residual stresses & quench cracking
Martempering or marquenching is a heat treatment designed to reduce:
residual stresses & quench cracking.
The quench medium in the Jominy test is
room temperature water
(Hypothetical Phase Diagram) -- Alpha Phase (a)
single phase solid solution of B in A
On a cooling curve for a Cu-Ni alloy the liquidus and solidus temperatures appear as ____
slope changes
Superplastic forming would be most appropriate for
small quantity; slow rate production
Fast cooling tends to promote nucleation and results in
smaller grains and stronger material
(Lead-Tin (Pb-Sn) diagram) -- Increasing the cooling rate of a eutectic material will produce a structure with ____ interlamellar spacing (or layer thickness) and ____ strenght
smaller, higher
Ideally, we would like the matrix of an age hardenable alloy to be:
soft and ductile
The temperature at which a material is fully solidified is called the
solidus
Austenitizing is similar to this step in the age hardening sequence
solution treatment
Steel A has a flat hardenability curve and a maximum hardness of Rockwell C 35. Steel B has a hardenability curve that drops off quickly as Jd increases, but a maximum hardness of Rockwell C 65. The steel with the highest carbon content would be:
steel A
Steel A has a flat hardenability curve and a maximum hardness of Rockwell C 35. Steel B has a hardenability curve that drops off quickly as Jd increases, but a maximum hardness of Rockwell C 65. The steel with the highest alloy content would be:
steel B
For a specific metal, increasing the percent cold work would result in a metal ___________ the same metal with less cold work:
stronger than
Pearlite is ___ ferrite.
stronger than
Solid solution strengthening occurs through the addition of this type of defect
substitutional or interstitial point defects
The "standard" format of phase diagras used in this course will be a plot of
temperature vs. composition (chemistry) at 1 atmospheric pressure
When two phases are present in a material, the compositions (chemistry) of each phase can be determined by
the end points of a tie line (end points)
Hot working is defined as deformation performed at a temperature above:
the recrystallization temp.
The carbon content of martensite is
the same as the austenite from which it formed
Boeing utilizes "Cold Spray" for structural component corrosion repair. Which of these is not a benefit of the cold spray process?
the surface is heated and residual stresses are relieved
When a hot piece of metal is immersed in a liquid quenchant (with the metal temperature above the liquid boiling point), the initial stage of cooling is called:
vapor jacket
When a material solidifies, there is a release of energy proportional to the ___, but energy must be provided that is proportional to the ____.
volume of solid; new interfacial surface area
When a material solidifies, there is a release of energy proportional to the ____, but the energy must be provided that is proportional to the ____.
volume of solid; new interfacial surface area
An equilibrium phase diagram can be used to determine
what phases will be present for each condition of chemistry and temperature, where phase transitions (such as melting) will occur, the chemistry and amount of each phase present at any condition
Because all of the high carbon is in the form of Fe3C, this type of cast iron is extremely hard and is used almost exclusively for its outstanding wear resistance.
white
According to Schmid's Law, the most favorable condition for slip to occur is:
λ = φ = 45o