Quiz 4 Flashcards
Phase diagrams provide the following information:
what phases exist at what temperatures
what phases exist at what concentrations of materials
what microstructure is present at a given material concentration & temperature
none of the choices listed
what phases exist at what temperatures
what phases exist at what concentrations of materials
what microstructure is present at a given material concentration & temperature
Phase diagrams provide answers to what questions?
what phase(s) are present
what are the components of the system
what are the degrees of freedom
what are the state variables
what phase(s) are present
what are the components of the system
what are the degrees of freedom
what are the state variables
What’s the best definition of a phase?
something either solid, liquid or gas
a chemically & structurally homogeneous portion of the microstructure
a chemically & physically uniform or homogeneous quantity of matter that can be mechanically separated from a nonhomogeneous mixture and may consist of a single substance or a mixture of substances
none of the choices listed
a chemically & physically uniform or homogeneous quantity of matter that can be mechanically separated from a nonhomogeneous mixture and may consist of a single substance or a mixture of substances
How many phases are shown in the micrograph of commercially pure Mo?
image 3
1
2
3
4
cannot be discerned from the information provided
0
1
Cu and Ni are soluble in each other. How many phases are in the Cu-Ni alloy shown below?
image 4
1
2
3
cannot be discerned from the information provided
0
1
MgO and NiO are soluble in each other. How many phases are in the MgO - NiO material shown below?
image 5
1
2
3
cannot discern based on the information provided
0
1
How many phases are present in the C-Fe system shown below?
image 6
1
2
3
cannot discern from the information provided
2
Why are engineers interested in the number of degrees of freedom of a system?
basic science reasons
esoteric reasons
other reasons not listed
control reasons
undisclosed reasons
capricious reasons
control reasons
What variables listed below are “state” variables?
KY sales tax rate
temperature
KY income tax rate
pressure
atomic number
composition
valence of outer shell electrons
pressure, temperature, composition
Which of the following best represents the most general form of the Gibbs Phase Rule?
F = C + P- 2
F = C - P + 1
F = P - C + 2
F = P + C – 2
F = C - P + 2
F = C - P + 2
Given that most materials engineering studies are conducted at 1 atmosphere pressure, what is the Gibbs Phase Rule for this particular condition?
F = C + P + 1
F = C - P + 2
F = C - P + 3
F = C - P + 1
F = P - C + 1
F = C - P + 1
If a system at atmospheric pressure contains a pure metal at it’s melting point, how many degrees of freedom exist?
0
1
2
3
unable to discern given the information provided
0
Complete the sentence that follows: a phase diagram is a graphic representation of the (fill in the blank) and associated microstructures as provided through the (fill in the blank)
constituents, Arrhenius relationship
constituents, Gibbs Phase Rule
state variables, Gibbs Phase Rule
state variables, Hume-Rothery rules
none of the above, none of the above
state variables, Gibbs Phase Rule
Phase diagrams are used for all of the following except:
metals
ceramics
polymers
none of the above - phase diagrams are useful for all solid materials
polymers
Phase diagrams are not used for polymers because these materials typically have only 1 component or (fill in the blank) structures not amenable to a phase diagram.
complex
long-chain
non-equilibrium
cross-linked
contorted (chains folded upon each other)
none of the choices listed
non-equilibrium
Points on a phase diagram that have specific temperature and pressure and composition are called…
phases
structures
state-points
fields
coordinates
state-points
Most of the commonly used engineering phase diagrams are simple maps at one atmosphere that provide engineers with quick visual aids for determining changes in phases and microstructure following changes in the most important state variables which are:
temperature
pressure
composition
homoscedasticity
normality
temperature, composition
Regarding the figure shown below, what is the line separating the alpha+liquid and alpha only region called?
image 7
liquidus
solidus
state line
tie line
Mason-Dixon line
38th parallel line
“I walk the line” (Johnny Cash)
solidus
Regarding the figure shown below, what region(s) of this figure encompass the state points? Choose all that may apply.
image 7
region above the liquidus line
region below the solidus line
region between the solidus & liquidus lines
all regions because phase diagrams represent all concentrations at all temperatures
region between the solidus & liquidus lines
In the phase diagram below, why does the microstructure of the polycrystalline solid appear as shown?
image 8
A and B are both completely soluble in each other in liquid form
A and B are both completely soluble in each other in solid form
A and B are both partially soluble in each other in liquid form
A and B are both partially soluble in each other in solid form
A and B are not soluble in each other in liquid form
A and B are not soluble in each other in solid form
A and B are both completely soluble in each other in solid form
In the phase diagram shown below, how many degrees of freedom exist at point L?
image 8
0
1
2
3
unable to tell given the information provided
1
What are the factors that matter concerning the microstructure that represents region SS of the “typical” engineering phase diagram illustrated below?
image 8
size matters
structure matters
valence electrons matter
pressure matters
concentration matters
electron thirst matters
temperature matters
size matters, structure matters, valence electrons matter, electron thirst matters
Determination of solubility of A and B in the phase diagram shown below is best aided using the:
image 8
Hall-Petch rule
Griffin Criterion
Boltzmann Distribution
Hume-Rothery Rules
crystal structure, packing and slip rules
another set of rules not listed here
Hume-Rothery Rules
In the figure shown below, what is the name of the line connecting points L and SS?
image 8
liquidus
solidus
state variable
tie
Mason-Dixon
“I walk the line” (Johnny Cash)
tie
True or False: There is not a well defined eutectic point in the phase diagram shown below: Image 9
False
Regarding the following phase diagram, what is the approximate eutectic temperature (degrees C)?
image 10
1,538
1,495
1,225
1,150
727
another value not shown
1150
What is the approximate composition of the eutectic point in the phase diagram shown?
image 9
100 % A
70% A
50% A
20% A
80% B
100% B
70% A
The following phase diagram may represent either the Ni - Cu system or the Sb - Bi system. Given the point M sub T on this diagram (intersection of the black dashed lines), what is the composition of the liquid at this temperature T?
image 11
X
C sub X
C
C sub Y
C sub 1
C sub 2
C sub Y
The following phase diagram may represent either the Ni - Cu system or the Sb - Bi system. Given the point M sub T on this diagram (intersection of the black dashed lines, what is the composition of the solid at this temperature T?
image 11
100% A
C sub X
C
C sub Y
C sub 1
C sub 2
100% B
C sub X
The following phase diagram may represent either the Ni - Cu system or the Sb - Bi system. Given the point M sub T on this diagram (intersection of the black dashed lines, what is the composition of the system at this temperature T?
image 11
100% A
C sub X
C
C sub Y
C sub 1
C sub 2
100% B
C
Given the following phase diagram and an approximate 20% mole NiO content and an approximate 2,200 degrees C temperature, what would the materials engineer expect to find?
image 12
single phase liquid
2 phase liquid
liquid and solid
2 phase solid
single phase solid
single phase solid
Regarding the following phase diagram, what is the approximate eutectoid temperature (degrees C)?
image 13
1,538
1,495
1,225
1,148
727
another value not shown
727
Assuming a binary compound of A and B (100% A on the left side of the abscissa, 100% B on the right side of the abscissa), what is the approximate composition of A in the (fill in the blank) at point 1?
image 14
liquid, 35%
liquid, 65%
liquid & solid, 35%
liquid & solid, 65%
none of the choices listed
liquid, 35%
Assuming a binary compound of A and B as noted previously, what will the materials engineer find at point 2 on this phase diagram?
image 14
liquid only
solid only
liquid and solid
liquid and solid phase beta
liquid and solid phase beta
Assuming a binary compound of A and B as noted previously, what is the approximate concentration of the solid phases beta at temperature T sub 2 (i.e. point 2) on the phase diagram?
image 14
50%
55%
65%
75%
85%
95%
100%
answer cannot be discerned from this phase diagram
95%
Assuming a binary compound of A and B as noted previously, what will the materials engineer find at point 3 on this phase diagram?
image 14
liquid only
solid only
liquid and solid
liquid and solid phase beta
cannot discern from this phase diagram
liquid and solid phase beta
Given the binary compound of A and B as noted previously, what principle will you use to determine the fraction of liquid phase at temperature T sub 3 denoted by point 3 on this phase diagram?
image 14
Hume-Rothery rule
Hall-Petch rule
lever rule
there is no rule needed to find this fraction
Griffin rule
lever rule
Given the binary compound of A and B as noted previously, what is the fraction of liquid phase at temperature T sub 3 denoted by point 3 on this phase diagram? Assume the “tie line” (the answer to the prior question) intersections the phase boundaries at 58% and 92%. Assume also that the blue vertical line intersects the abscissa at the 65% level.
image 14
20%
35%
50%
58%
65%
80%
92%
95%
cannot determine based on information provided
80%
Given the binary compound of A and B as noted previously, what is the fraction of solid phase beta at temperature T sub 3 denoted by point 3 on this phase diagram? Assume the “tie line” (the answer to the prior question) intersections the phase boundaries at 58% and 92%. Assume also that the blue vertical line intersects the abscissa at the 65% level. Hint: well prepared students who studied the notes well and understand the material and who are certain of the prior question’s answer can solve this problem easily.
image 14
20%
35%
50%
58%
65%
80%
95%
cannot determine based upon information provided
20%
The binary compound of A and B noted previously now cools to temperature T sub 4 denoted by point 4 on the phase diagram shown. What is the name of the temperature that exists at approximately 50% concentration of A?.
image 14
melting temperature
eutectoid temperature
all liquid temperature
eutectic temperature
ductile-brittle temperature
glass transition temperature
another name not listed
eutectic temperature
The binary compound of A and B cools to the eutectic temperature T sub 4 denoted by point 4 on the phase diagram shown. What is present at this temperature?
image 14
liquid only
solid only
liquid and solid
liquid and 2 phases
liquid + solid phase alpha + solid phase beta
this is one of those regions where the phase diagram fails to provide this information
liquid + solid phase alpha + solid phase beta
The binary compound of A and B cools to the eutectic temperature T sub 4 denoted by point 4 on the phase diagram shown. What is the fraction of solid phase beta at this temperature? Assume the eutectic temperature T sub 4 occurs at a concentration of 48% B, the blue vertical line occurs as noted previously occurs at 65% B and the tie line intersects the beta+L/beta/alpha+beta triple intersection at 87% B..
image 14
35%
44%
53%
62%
71%
80%
87%
96%
answer cannot be discerned from the information provided
44%
The binary compound of A and B cools below the eutectic temperature to the temperature T sub 5 denoted by point 5 on the phase diagram shown. What is present at this temperature?
image 14
liquid only
solid only
solid phase alpha + liquid
solid phase beta + liquid
solid phase alpha + solid phase beta
solid phase alpha + solid phase beta
The binary compound of A and B cools below the eutectic temperature to the temperature T sub 5 denoted by point 5 on the phase diagram shown. What is the fraction of solid phase alpha present at this temperature? Assume the dashed blue vertical line represents 65% B and the tie line positioned at T sub 5 intersects the alpha/alpha+beta line at 9% B and it also intersects the beta/alpha+beta line at 91% B.
image 14
9%
21%
32%
44%
50%
68%
80%
96%
cannot be determined from the information provided
32%
