MSE 250 EXAM 4 QUESTIONS AND ANSWERS
1. Phase diagrams can be used to identify alloys that are eligible for .- Ans
2. ..Certain metal alloys can be strengthened using and .-
Answer - a. supersaturation; precipitation
3. We can use phase diagrams and graphs to predict the effects of an
on the strength of age-hardened alloys.- Answer - b. strength vs. time; temperature; time
4. Why do blacksmiths dip hot metal objects in water? To them, in
order to
them.- Answer - b. quench; strengthen
5. We can obtain different by cooling steel at different .- Answer - d.
microstructures; rates
6. Nucleation and crystal growth are affected by quench and
cooling .- Answer -
a. temperature; rates
7. We can control the strength of a steel part by manipulating its
of .-
Answer - c. rate; cooling
8. Martensite is caused by a change in , not by of carbon.- Answer - e. crystal
structure; dittusion
9. Aluminum can be age hardened by adding 0.5% of Mg and 4% of , and
.- Answer - a. Cu; 520; 24 hours
10. The first aerospace aluminum alloy, used in the Wright airplane crankcase,
used hardening to strengthen the alloy- Answer - c. precipitation
11. Phase diagrams of age-hardenable alloys must show solid-
solubility with
, temperature.- Answer - d. decreasing; decreasing
12. The strength of an age-hardened alloy with increasing ageing time
at temperature, then reaches a , and then after that.- Answer - a. increases;
maximum; decreases
13. The hardness of an age-hardened alloy with increasing ageing time
at temperature, then reaches a , and then after that.- Answer - a. increases;
maximum; decreases
14. An age-hardening alloy starts off as a before it age-hardens over
time.- Answer - d. supersaturated solid-solution
15. After a short period of ageing at temperature, an age-hardened alloy is
underaged, and has and precipitates.- Answer - e. small;
underdeveloped
16. After an optimum period of ageing at temperature, an age-hardened alloy
is peak-aged, and has and precipitates for strengthening of the alloy.-
Answer - b. the optimum size; distribution of
,17. After too long of a period of ageing at temperature, an age-hardened alloy
is over-aged, and experience of precipitates.- Answer - a. coarsening
18. Age hardened alloys can be used for bicycle , cookware,
and in integrated circuit
chips.- Answer - b. frames; metal; metal interconnects
19. Precipitation hardening works by a mechanism where impede .- Ans
20. Precipitation hardening is used in the system.- Answer - b. Al-Cu
21. Precipitation hardening is used in the system.- Answer - c. Mg-Al
22. The first phase of precipitation hardening of Al-Cu is to the alloy
to form a .- Answer -
c. solution heat-treat; single-phase solid-solution
23. The second phase of precipitation hardening of Al-Cu is to the
alloy to .- Answer
- b. quench; room-temperature
24. The third phase precipitation hardening of Al-Cu is to the alloy to a
small precipitates within the Al matrix.- Answer - c. reheat; nucleate; grow; theta-phase
25. During precipitation hardening of Al-Cu, the strength of the alloy as t
26. During precipitation hardening of Al-Cu, the hardness of the alloy as the
precipitates and initially in size, until they reach .- Answer - a. increases;
nucleate; grow; an optimum size
27. During precipitation hardening of Al-Cu, the strength of the alloy as the
precipitates beyond the .- Answer - c. decreases a bit; coarsens; optimum size
28. During precipitation hardening of Al-Cu, the hardness of the alloy as the
precipitates beyond the .- Answer - c. decreases a bit; coarsens; optimum size
29. An Al-Cu alloy with a small wt% Cu, develops theta-double-prime phase
regions when it is heat-treated. This phase is and with the
, alpha-phase lattice.- Answer - a. disordered; coherent
30. The theta- double prime phase creates strain fields in the
Aluminum matrix- Answer - b. large
31. Upon further heat-treatment, the theta phase forms in the Al-Cu alloy. The
theta phase is and with the aluminum lattice.- Answer - b. ordered;
incoherent
1. Phase diagrams can be used to identify alloys that are eligible for .- Ans
2. ..Certain metal alloys can be strengthened using and .-
Answer - a. supersaturation; precipitation
3. We can use phase diagrams and graphs to predict the effects of an
on the strength of age-hardened alloys.- Answer - b. strength vs. time; temperature; time
4. Why do blacksmiths dip hot metal objects in water? To them, in
order to
them.- Answer - b. quench; strengthen
5. We can obtain different by cooling steel at different .- Answer - d.
microstructures; rates
6. Nucleation and crystal growth are affected by quench and
cooling .- Answer -
a. temperature; rates
7. We can control the strength of a steel part by manipulating its
of .-
Answer - c. rate; cooling
8. Martensite is caused by a change in , not by of carbon.- Answer - e. crystal
structure; dittusion
9. Aluminum can be age hardened by adding 0.5% of Mg and 4% of , and
.- Answer - a. Cu; 520; 24 hours
10. The first aerospace aluminum alloy, used in the Wright airplane crankcase,
used hardening to strengthen the alloy- Answer - c. precipitation
11. Phase diagrams of age-hardenable alloys must show solid-
solubility with
, temperature.- Answer - d. decreasing; decreasing
12. The strength of an age-hardened alloy with increasing ageing time
at temperature, then reaches a , and then after that.- Answer - a. increases;
maximum; decreases
13. The hardness of an age-hardened alloy with increasing ageing time
at temperature, then reaches a , and then after that.- Answer - a. increases;
maximum; decreases
14. An age-hardening alloy starts off as a before it age-hardens over
time.- Answer - d. supersaturated solid-solution
15. After a short period of ageing at temperature, an age-hardened alloy is
underaged, and has and precipitates.- Answer - e. small;
underdeveloped
16. After an optimum period of ageing at temperature, an age-hardened alloy
is peak-aged, and has and precipitates for strengthening of the alloy.-
Answer - b. the optimum size; distribution of
,17. After too long of a period of ageing at temperature, an age-hardened alloy
is over-aged, and experience of precipitates.- Answer - a. coarsening
18. Age hardened alloys can be used for bicycle , cookware,
and in integrated circuit
chips.- Answer - b. frames; metal; metal interconnects
19. Precipitation hardening works by a mechanism where impede .- Ans
20. Precipitation hardening is used in the system.- Answer - b. Al-Cu
21. Precipitation hardening is used in the system.- Answer - c. Mg-Al
22. The first phase of precipitation hardening of Al-Cu is to the alloy
to form a .- Answer -
c. solution heat-treat; single-phase solid-solution
23. The second phase of precipitation hardening of Al-Cu is to the
alloy to .- Answer
- b. quench; room-temperature
24. The third phase precipitation hardening of Al-Cu is to the alloy to a
small precipitates within the Al matrix.- Answer - c. reheat; nucleate; grow; theta-phase
25. During precipitation hardening of Al-Cu, the strength of the alloy as t
26. During precipitation hardening of Al-Cu, the hardness of the alloy as the
precipitates and initially in size, until they reach .- Answer - a. increases;
nucleate; grow; an optimum size
27. During precipitation hardening of Al-Cu, the strength of the alloy as the
precipitates beyond the .- Answer - c. decreases a bit; coarsens; optimum size
28. During precipitation hardening of Al-Cu, the hardness of the alloy as the
precipitates beyond the .- Answer - c. decreases a bit; coarsens; optimum size
29. An Al-Cu alloy with a small wt% Cu, develops theta-double-prime phase
regions when it is heat-treated. This phase is and with the
, alpha-phase lattice.- Answer - a. disordered; coherent
30. The theta- double prime phase creates strain fields in the
Aluminum matrix- Answer - b. large
31. Upon further heat-treatment, the theta phase forms in the Al-Cu alloy. The
theta phase is and with the aluminum lattice.- Answer - b. ordered;
incoherent
