MSE 250 - EXAM 4 QUESTIONS & ANSWERS
Phase diagrams can be used to identify alloys that are eligible for __.
a. age softening
b. pressure hardening
c. age hardening
d. pressure softening
e. none of the above - Answer -c. age hardening
Certain metal alloys can be strengthened using __ and __.
a. supersaturation; precipitation
b. undersaturation; precipitation
c. undersaturation; dissolution
d. supersaturation; dissolution
e. none of the above - Answer -a. supersaturation; precipitation
We can use phase diagrams and __ graphs to predict the effects of __ and __ on the
strength of age-hardened alloys.
a. phase-transformation; phases; transformations
b. strength vs. time; temperature; time
c. phase-transformation; temperature; time
d. isothermal-transformation; isotherms; isochrons
e. none of the above - Answer -b. strength vs. time; temperature; time
Why do blacksmiths dip hot metal objects in water? To __ them, in order to __ them.
a. anneal; strengthen
b. quench; strengthen
c. anneal; increase ductility
d. quench; increase ductility
e. none of the above - Answer -b. quench; strengthen
We can obtain different __ by cooling steel at different __.
a. transmutations; isotherms
b. transmutations; rates
c. microstructures; isotherms
d. microstructures; rates
e. none of the above - Answer -d. microstructures; rates
Nucleation and crystal growth are affected by quench __ and cooling __.
a. temperature; rates
b. density; mass
c. pressure; volume
d. time; temperature
e. none of the above - Answer -a. temperature; rates
,We can control the strength of a steel part by manipulating its __ of __.
a. isotherm; cooling
b. isotherm; heating
c. rate; cooling
d. microstructure; cooling
e. none of the above - Answer -c. rate; cooling
Martensite is caused by a change in __, not by __ of carbon.
a. transmuted elements; formation
b. formation of elements; volume
c. diffusion; crystal structure
d. crystal structure; melting
e. crystal structure; diffusion - Answer -e. crystal structure; diffusion
Aluminum can be age hardened by adding 0.5% of Mg and 4% of __, and quenching it
from a temperature of __ degrees C, and then letting it age over __.
a. Cu; 520; 24 hours
b. Fe; 52; 24 days
c. Pb; 5; 24 hours
d. Na; 5200; 24 days
e. none of the above - Answer -a. Cu; 520; 24 hours
The first aerospace aluminum alloy, used in the Wright airplane crankcase, used __
hardening to strengthen the alloy.
a. martensitic
b. cementite
c. precipitation
d. work
e. none of the above - Answer -c. precipitation
Phase diagrams of age-hardenable alloys must show __ solid-solubility with __
temperature.
a. increasing; decreasing
b. constant; increasing
c. infinite; decreasing
d. decreasing; decreasing
e. none of the above - Answer -d. decreasing; decreasing
The strength of an age-hardened alloy __ with increasing ageing time at temperature,
then reaches a __, and then __ after that.
a. increases; maximum; decreases
b. decreases; minimum; increases
c. decreases; plateau; decreases
d. increases; plateau; increases
e. none of the above - Answer -a. increases; maximum; decreases
,The hardness of an age-hardened alloy __ with increasing ageing time at temperature,
then reaches a __, and then __ after that.
a. increases; maximum; decreases
b. decreases; minimum; increases
c. decreases; plateau; decreases
d. increases; plateau; increases
e. none of the above - Answer -a. increases; maximum; decreases
An age-hardening alloy starts off as a __ before it age-hardens over time.
a. undersaturated liquid-solution
b. saturated solid-solution
c. supersaturated liquid-solution
d. supersaturated solid-solution
e. none of the above - Answer -d. supersaturated solid-solution
After a short period of ageing at temperature, an age-hardened alloy is underaged, and
has __ and __ precipitates.
a. globular; liquid-phase
b. large; underdeveloped
c. small; overdeveloped
d. large; overdeveloped
e. small; underdeveloped - Answer -e. small; underdeveloped
After an optimum period of ageing at temperature, an age-hardened alloy is peak-aged,
and has __ and __ precipitates for strengthening of the alloy.
a. a minimum size; a wide distribution of
b. the optimum size; distribution of
c. a maximum size; a narrow distribution of
d. a minimum size; a narrow distribution of
e. none of the above - Answer -b. the optimum size; distribution of
After too long of a period of ageing at temperature, an age-hardened alloy is over-aged,
and experiences __ of precipitates.
a. coarsening
b. fine-sizing
c. preferential elongation
d. lenticularization
e. none of the above - Answer -a. coarsening
Age hardened alloys can be used for bicycle __, __ cookware, and __ in integrated
circuit chips.
a. seats; ceramic; semiconductor transistors
b. frames; metal; metal interconnects
c. tires; ceramic; superconductor junctions
d. frames; polymer; electrical junctions
e. none of the above - Answer -b. frames; metal; metal interconnects
, Precipitation hardening works by a mechanism where __ impede __.
a. precipitates; dislocation motion
b. precipitates; dislocation formation
c. dislocations; precipitate motion
d. vacancies; dislocation creation
e. none of the above - Answer -a. precipitates; dislocation motion
Precipitation hardening is used in the __ system.
a. Cu-Cu
b. Al-Cu
c. Fe-Cu
d. CH3OH
e. none of the above - Answer -b. Al-Cu
Precipitation hardening is used in the __ system.
a. Cu-Cu
b. C2H6
c. Mg-Al
d. CH3OH
e. none of the above - Answer -c. Mg-Al
The first phase of precipitation hardening of Al-Cu is to __ the alloy to form a __ .
a. solution quench; single-phase liquid
b. dissolution quench; two-phase solid-solution
c. solution heat-treat; single-phase solid-solution
d. dissolution heat-treat; two-phase liquid
e. none of the above - Answer -c. solution heat-treat; single-phase solid-solution
The second phase of precipitation hardening of Al-Cu is to __ the alloy to __.
a. solution quench; form a single-phase liquid
b. quench; room-temperature
c. solution heat-treat; form a single-phase solid-solution
d. heat; melting point
e. none of the above - Answer -b. quench; room-temperature
The third phase of precipitation hardening of Al-Cu is to __ the alloy to __ and __ small
__ precipitates within the Al matrix.
a. slowly cool; nucleate; grow; theta-phase
b. reheat; dissolve; remove; Al
c. reheat; nucleate; grow; theta-phase
d. rapidly quench; dissolve; remove; Cu
e. none of the above - Answer -c. reheat; nucleate; grow; theta-phase
During precipitation hardening of Al-Cu, the strength of the alloy __ as the precipitates
__ and initially __ in size, until they reach __.
Phase diagrams can be used to identify alloys that are eligible for __.
a. age softening
b. pressure hardening
c. age hardening
d. pressure softening
e. none of the above - Answer -c. age hardening
Certain metal alloys can be strengthened using __ and __.
a. supersaturation; precipitation
b. undersaturation; precipitation
c. undersaturation; dissolution
d. supersaturation; dissolution
e. none of the above - Answer -a. supersaturation; precipitation
We can use phase diagrams and __ graphs to predict the effects of __ and __ on the
strength of age-hardened alloys.
a. phase-transformation; phases; transformations
b. strength vs. time; temperature; time
c. phase-transformation; temperature; time
d. isothermal-transformation; isotherms; isochrons
e. none of the above - Answer -b. strength vs. time; temperature; time
Why do blacksmiths dip hot metal objects in water? To __ them, in order to __ them.
a. anneal; strengthen
b. quench; strengthen
c. anneal; increase ductility
d. quench; increase ductility
e. none of the above - Answer -b. quench; strengthen
We can obtain different __ by cooling steel at different __.
a. transmutations; isotherms
b. transmutations; rates
c. microstructures; isotherms
d. microstructures; rates
e. none of the above - Answer -d. microstructures; rates
Nucleation and crystal growth are affected by quench __ and cooling __.
a. temperature; rates
b. density; mass
c. pressure; volume
d. time; temperature
e. none of the above - Answer -a. temperature; rates
,We can control the strength of a steel part by manipulating its __ of __.
a. isotherm; cooling
b. isotherm; heating
c. rate; cooling
d. microstructure; cooling
e. none of the above - Answer -c. rate; cooling
Martensite is caused by a change in __, not by __ of carbon.
a. transmuted elements; formation
b. formation of elements; volume
c. diffusion; crystal structure
d. crystal structure; melting
e. crystal structure; diffusion - Answer -e. crystal structure; diffusion
Aluminum can be age hardened by adding 0.5% of Mg and 4% of __, and quenching it
from a temperature of __ degrees C, and then letting it age over __.
a. Cu; 520; 24 hours
b. Fe; 52; 24 days
c. Pb; 5; 24 hours
d. Na; 5200; 24 days
e. none of the above - Answer -a. Cu; 520; 24 hours
The first aerospace aluminum alloy, used in the Wright airplane crankcase, used __
hardening to strengthen the alloy.
a. martensitic
b. cementite
c. precipitation
d. work
e. none of the above - Answer -c. precipitation
Phase diagrams of age-hardenable alloys must show __ solid-solubility with __
temperature.
a. increasing; decreasing
b. constant; increasing
c. infinite; decreasing
d. decreasing; decreasing
e. none of the above - Answer -d. decreasing; decreasing
The strength of an age-hardened alloy __ with increasing ageing time at temperature,
then reaches a __, and then __ after that.
a. increases; maximum; decreases
b. decreases; minimum; increases
c. decreases; plateau; decreases
d. increases; plateau; increases
e. none of the above - Answer -a. increases; maximum; decreases
,The hardness of an age-hardened alloy __ with increasing ageing time at temperature,
then reaches a __, and then __ after that.
a. increases; maximum; decreases
b. decreases; minimum; increases
c. decreases; plateau; decreases
d. increases; plateau; increases
e. none of the above - Answer -a. increases; maximum; decreases
An age-hardening alloy starts off as a __ before it age-hardens over time.
a. undersaturated liquid-solution
b. saturated solid-solution
c. supersaturated liquid-solution
d. supersaturated solid-solution
e. none of the above - Answer -d. supersaturated solid-solution
After a short period of ageing at temperature, an age-hardened alloy is underaged, and
has __ and __ precipitates.
a. globular; liquid-phase
b. large; underdeveloped
c. small; overdeveloped
d. large; overdeveloped
e. small; underdeveloped - Answer -e. small; underdeveloped
After an optimum period of ageing at temperature, an age-hardened alloy is peak-aged,
and has __ and __ precipitates for strengthening of the alloy.
a. a minimum size; a wide distribution of
b. the optimum size; distribution of
c. a maximum size; a narrow distribution of
d. a minimum size; a narrow distribution of
e. none of the above - Answer -b. the optimum size; distribution of
After too long of a period of ageing at temperature, an age-hardened alloy is over-aged,
and experiences __ of precipitates.
a. coarsening
b. fine-sizing
c. preferential elongation
d. lenticularization
e. none of the above - Answer -a. coarsening
Age hardened alloys can be used for bicycle __, __ cookware, and __ in integrated
circuit chips.
a. seats; ceramic; semiconductor transistors
b. frames; metal; metal interconnects
c. tires; ceramic; superconductor junctions
d. frames; polymer; electrical junctions
e. none of the above - Answer -b. frames; metal; metal interconnects
, Precipitation hardening works by a mechanism where __ impede __.
a. precipitates; dislocation motion
b. precipitates; dislocation formation
c. dislocations; precipitate motion
d. vacancies; dislocation creation
e. none of the above - Answer -a. precipitates; dislocation motion
Precipitation hardening is used in the __ system.
a. Cu-Cu
b. Al-Cu
c. Fe-Cu
d. CH3OH
e. none of the above - Answer -b. Al-Cu
Precipitation hardening is used in the __ system.
a. Cu-Cu
b. C2H6
c. Mg-Al
d. CH3OH
e. none of the above - Answer -c. Mg-Al
The first phase of precipitation hardening of Al-Cu is to __ the alloy to form a __ .
a. solution quench; single-phase liquid
b. dissolution quench; two-phase solid-solution
c. solution heat-treat; single-phase solid-solution
d. dissolution heat-treat; two-phase liquid
e. none of the above - Answer -c. solution heat-treat; single-phase solid-solution
The second phase of precipitation hardening of Al-Cu is to __ the alloy to __.
a. solution quench; form a single-phase liquid
b. quench; room-temperature
c. solution heat-treat; form a single-phase solid-solution
d. heat; melting point
e. none of the above - Answer -b. quench; room-temperature
The third phase of precipitation hardening of Al-Cu is to __ the alloy to __ and __ small
__ precipitates within the Al matrix.
a. slowly cool; nucleate; grow; theta-phase
b. reheat; dissolve; remove; Al
c. reheat; nucleate; grow; theta-phase
d. rapidly quench; dissolve; remove; Cu
e. none of the above - Answer -c. reheat; nucleate; grow; theta-phase
During precipitation hardening of Al-Cu, the strength of the alloy __ as the precipitates
__ and initially __ in size, until they reach __.
