Metallurgy Exam 2
The increase in strength observed during cold work or strain hardening is primarily due
to a vast increase in the number or amount of: - Answer dislocations
If we deform a metal in successive increments the yield strength will incrementally: -
Answer increase
If a small amount of cold work produces a large increase in strength, the strain
hardening coefficient, n, would be ___. - Answer high
Cold work strengthening is highly effective for metals with this crystal structure: -
Answer FCC
A flat plate of metal is cold-rolled from 1-inch thick to 1/2-inch and then further to 1/4-
inch, with no increase in width. The total amount of cold work performed is: - Answer
75%
Which of the following is not an asset of cold working? - Answer All materials can be
strengthened (metals, ceramics, polymers & composites).
Which of the following is not a correct statement regarding cold work? - Answer The
amount of deformation is essentially unlimited.
Cold worked components usually have ___ properties. - Answer anisotropic
Anisotropy and the residual stresses produced by cold working: - Answer may be
advantageous or detrimental
If we heat a cold worked material into the diffusion range, the cold worked structure: -
Answer will change with time
During which stage of annealing are there no "optically-observable" changes to the
structure, but some properties do change? - Answer Recovery
During which stage of annealing are the effects of strain hardening removed and
ductility restored? - Answer Recrystallization
Which stage of annealing is usually considered to be undesirable? - Answer Grain
growth
During which stage of annealing are the residual stresses produced during cold working
eliminated, but the strengthening of strain hardening is retained? - Answer Recovery
, During which stage of annealing do dislocations move, but do not decrease in amount. -
Answer Recovery
During which stage of annealing are new grains nucleated and grown? - Answer
Recrystallization
During which stage of annealing are the number or density of dislocations decreased
dramatically? - Answer Recrystallization
Which of the following is a correct statement regarding the joining of cold worked
material? - Answer To retain mechanical properties, cold worked materials should only
be joined by low temperature joining methods.
Hot working is defined as deformation performed at a temperature above: - Answer the
recrystallization temp
Which of the following is not a true statement about hot working? - Answer Surface
finish and dimensional precision are good
The "deformation mechanism" associated with superplastic behavior is: - Answer grain
boundary sliding.
Superplastic forming would be most appropriate for: - Answer small quantity; slow rate
production
When a material solidifies, there is a release of energy proportional to the ___, but
energy must be provided that is proportional to the ____. - Answer volume of solid; new
interfacial surface area
If the size of an "embryo" is smaller than the critical radius, it will: - Answer remelt
If we drop the temperature further below the melting temperature (undercool), the size
of the critical radius will: - Answer decrease
To achieve homogeneous nucleation generally would require: - Answer undercooling of
about 0.2 times the melting point on an absolute scale.
Heterogeneous nucleation requires ___ undercooling than homogeneous nucleation. -
Answer less
This type of nucleation is rarely observed during normal solidification: - Answer
Homogeneous
Inoculation is a means of promoting _____ nucleation. - Answer heterogeneous
The production of an amorphous structure requires: - Answer extremely fast cooling.
The increase in strength observed during cold work or strain hardening is primarily due
to a vast increase in the number or amount of: - Answer dislocations
If we deform a metal in successive increments the yield strength will incrementally: -
Answer increase
If a small amount of cold work produces a large increase in strength, the strain
hardening coefficient, n, would be ___. - Answer high
Cold work strengthening is highly effective for metals with this crystal structure: -
Answer FCC
A flat plate of metal is cold-rolled from 1-inch thick to 1/2-inch and then further to 1/4-
inch, with no increase in width. The total amount of cold work performed is: - Answer
75%
Which of the following is not an asset of cold working? - Answer All materials can be
strengthened (metals, ceramics, polymers & composites).
Which of the following is not a correct statement regarding cold work? - Answer The
amount of deformation is essentially unlimited.
Cold worked components usually have ___ properties. - Answer anisotropic
Anisotropy and the residual stresses produced by cold working: - Answer may be
advantageous or detrimental
If we heat a cold worked material into the diffusion range, the cold worked structure: -
Answer will change with time
During which stage of annealing are there no "optically-observable" changes to the
structure, but some properties do change? - Answer Recovery
During which stage of annealing are the effects of strain hardening removed and
ductility restored? - Answer Recrystallization
Which stage of annealing is usually considered to be undesirable? - Answer Grain
growth
During which stage of annealing are the residual stresses produced during cold working
eliminated, but the strengthening of strain hardening is retained? - Answer Recovery
, During which stage of annealing do dislocations move, but do not decrease in amount. -
Answer Recovery
During which stage of annealing are new grains nucleated and grown? - Answer
Recrystallization
During which stage of annealing are the number or density of dislocations decreased
dramatically? - Answer Recrystallization
Which of the following is a correct statement regarding the joining of cold worked
material? - Answer To retain mechanical properties, cold worked materials should only
be joined by low temperature joining methods.
Hot working is defined as deformation performed at a temperature above: - Answer the
recrystallization temp
Which of the following is not a true statement about hot working? - Answer Surface
finish and dimensional precision are good
The "deformation mechanism" associated with superplastic behavior is: - Answer grain
boundary sliding.
Superplastic forming would be most appropriate for: - Answer small quantity; slow rate
production
When a material solidifies, there is a release of energy proportional to the ___, but
energy must be provided that is proportional to the ____. - Answer volume of solid; new
interfacial surface area
If the size of an "embryo" is smaller than the critical radius, it will: - Answer remelt
If we drop the temperature further below the melting temperature (undercool), the size
of the critical radius will: - Answer decrease
To achieve homogeneous nucleation generally would require: - Answer undercooling of
about 0.2 times the melting point on an absolute scale.
Heterogeneous nucleation requires ___ undercooling than homogeneous nucleation. -
Answer less
This type of nucleation is rarely observed during normal solidification: - Answer
Homogeneous
Inoculation is a means of promoting _____ nucleation. - Answer heterogeneous
The production of an amorphous structure requires: - Answer extremely fast cooling.
