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