Materials Exam 4 Review questions
and answers graded A+ updated
the elements or compounds present in an alloy (e.g. Al and Cu, Al2O3 and MgO) - ANS ✔Define
components
a series of materials, varying in specific composition, but not in its components (e.g. iron-carbon
system) - ANS ✔Define system
The maximum concentration for which only a single phase exists - ANS ✔Solubility limit
a system in its most stable state - that is, its phase characteristics do not change over time.
Thermodynamically, the condition is that the free energy of a system is a minimum for some set
combination of temperature, pressure and composition. - ANS ✔phase equilibrium
A nonequilibrium state that may persist indefinitely and experience imperceptible changes with
time. - ANS ✔metastable
one-component phase diagrams, logarithm of the pressure is plotted versus the temperature;
solid-, liquid-, and vapor-phase regions are found on this type of diagram. - ANS ✔unary phase
diagrams
for binary systems, temperature and composition are variables, whereas external pressure is
held constant. Areas, or phase regions, are defined on these temperature-versus-composition
plots within which either one or two phases exist. - ANS ✔binary phase diagrams
complete liquid and solid solubility of the two components - ANS ✔isomorphous system
, homogeneous mixture with a lower melting point than either pure component - ANS ✔eutectic
system
an element of the microstructure having an identifiable and characteristic structure (e.g.
pearlite, primary phase, proeutectoid) - ANS ✔microconstituents
- ANS ✔can you identify the liquidus, solidus and solvus lines on isomorphous and eutectic
phase diagrams?
System: Cu-Ni
Components: 2 Cu and Ni
Phases: 2, L and alpha
Solubility limit: no limit in either L or alpha - ANS ✔Can you identify the system, components,
phases present (what are they), and the solubility limit of each component?
System: Cu-Ag
Components: 2 Cu and Ag
Phases: 3, L, alpha and beta (1 liquid and two solid)
Solubility limit: No limit in L, Ag in alpha phase given by solvus line BC, Cu in beta phase by
solvus line GH. - ANS ✔Can you identify the system, components, phases present (what are
they), and the solubility limit of each component?
(See exam 4 review pdf for examples) - ANS ✔Can you interpret a phase diagram (eutectic or
isomorphus), and determine the following at a given composition and temperature?
1. phase(s) present
2. composition of the phase(s)
3. mass fraction(s) of the phases
and answers graded A+ updated
the elements or compounds present in an alloy (e.g. Al and Cu, Al2O3 and MgO) - ANS ✔Define
components
a series of materials, varying in specific composition, but not in its components (e.g. iron-carbon
system) - ANS ✔Define system
The maximum concentration for which only a single phase exists - ANS ✔Solubility limit
a system in its most stable state - that is, its phase characteristics do not change over time.
Thermodynamically, the condition is that the free energy of a system is a minimum for some set
combination of temperature, pressure and composition. - ANS ✔phase equilibrium
A nonequilibrium state that may persist indefinitely and experience imperceptible changes with
time. - ANS ✔metastable
one-component phase diagrams, logarithm of the pressure is plotted versus the temperature;
solid-, liquid-, and vapor-phase regions are found on this type of diagram. - ANS ✔unary phase
diagrams
for binary systems, temperature and composition are variables, whereas external pressure is
held constant. Areas, or phase regions, are defined on these temperature-versus-composition
plots within which either one or two phases exist. - ANS ✔binary phase diagrams
complete liquid and solid solubility of the two components - ANS ✔isomorphous system
, homogeneous mixture with a lower melting point than either pure component - ANS ✔eutectic
system
an element of the microstructure having an identifiable and characteristic structure (e.g.
pearlite, primary phase, proeutectoid) - ANS ✔microconstituents
- ANS ✔can you identify the liquidus, solidus and solvus lines on isomorphous and eutectic
phase diagrams?
System: Cu-Ni
Components: 2 Cu and Ni
Phases: 2, L and alpha
Solubility limit: no limit in either L or alpha - ANS ✔Can you identify the system, components,
phases present (what are they), and the solubility limit of each component?
System: Cu-Ag
Components: 2 Cu and Ag
Phases: 3, L, alpha and beta (1 liquid and two solid)
Solubility limit: No limit in L, Ag in alpha phase given by solvus line BC, Cu in beta phase by
solvus line GH. - ANS ✔Can you identify the system, components, phases present (what are
they), and the solubility limit of each component?
(See exam 4 review pdf for examples) - ANS ✔Can you interpret a phase diagram (eutectic or
isomorphus), and determine the following at a given composition and temperature?
1. phase(s) present
2. composition of the phase(s)
3. mass fraction(s) of the phases
