MTE 271 EXAM 2 QUESTIONS WITH VERIFIED SOLUTIONS LATEST UPDATE 2026
A grain boundary is a - Answers 2D Defect
Which is not one of the Hume-Rothery Rules
A. Same valence
B. Similar crystal structure
C. Similar size
D. Similar electronegativity
E. None of the above - Answers B. Similar crystal Structure
Which variables control phase equilibrium in materials
A. Temperature
B. Pressure
C. Composition
D. All of the above
E. None of the above - Answers D. All of the above
A Frenkel defect is - Answers A vacancy-interstitial combination
The theoretical strength of a material is ______________ than the experimentally measured strength
- Answers Higher
A dislocation is defined by - Answers A burger vector & line sense vector
Fick's 1st Law of Diffusion - Answers Time independent diffusion
In general, diffusion is __________ a concentration gradient - Answers Down
As grains become small, the hardness of a material - Answers increases
A phase is best described as - Answers A homogenous portion of any system with uniform physical
and chemical characteristics
An alloy at the eutectic composition melts over a range of temperatures - Answers False
Martensite makes a steel - Answers Harder and more brittle
Strain is best described as - Answers A change in length over the original length
Elastic deformation refers to - Answers Non-permeant deformation
When the stress is given as a positive value - Answers The material is under tension
Diffusion is faster in - Answers Lower activation energy, Q, materials
Martensite in steels forms under - Answers Rapid cooling to room temperature from the FCC
austensite phase field
When the temperature lowers in a material, the number of vacancies - Answers Decreases linearly
with temperature
Tempering - Answers Increases the amount of martensite in a steel
Dislocations are the mechanisms that assist in the deformation of a material - Answers True
Which is not a type of dislocation - Answers tilt
Diffusion can occur in a metal when all the atoms are the same type - Answers True
A Schottky defect is - Answers A pair of oppositely charged ion vacancies
Cementite (Fe3C) is - Answers A hard, brittle phase in steels
When the stress is given as a negative values, - Answers The material is under compression
Diffusion is slower in/with - Answers Close-packed structures
In general, interstitial diffusion is slower than substitional diffusion - Answers False
Two fundamental types of dislocation - Answers Edge & Screw
It is possible to produce a perfect crystalline - Answers False
Slow cooling leads to - Answers Equilibrium
Fast cooling leads to - Answers Cored Structure
Diffusion is faster with secondary bonds - Answers True
For technologically important alloys, is a metastable or equilibrium state desired? - Answers
Metastable, more long lasting
0D Defects - Answers Point Defects (vacancies, , interstitials, substitutional)
1D Defects - Answers Line Defects (edge dislocations, screw dislocations)
2D Defects - Answers Planar Defects (grain boundaries, twin boundaries, phase boundaries, stacking
faults)
3D Defects - Answers Volume Defects (inclusions, porosity, voids, cracks)
A grain boundary is a - Answers 2D Defect
Which is not one of the Hume-Rothery Rules
A. Same valence
B. Similar crystal structure
C. Similar size
D. Similar electronegativity
E. None of the above - Answers B. Similar crystal Structure
Which variables control phase equilibrium in materials
A. Temperature
B. Pressure
C. Composition
D. All of the above
E. None of the above - Answers D. All of the above
A Frenkel defect is - Answers A vacancy-interstitial combination
The theoretical strength of a material is ______________ than the experimentally measured strength
- Answers Higher
A dislocation is defined by - Answers A burger vector & line sense vector
Fick's 1st Law of Diffusion - Answers Time independent diffusion
In general, diffusion is __________ a concentration gradient - Answers Down
As grains become small, the hardness of a material - Answers increases
A phase is best described as - Answers A homogenous portion of any system with uniform physical
and chemical characteristics
An alloy at the eutectic composition melts over a range of temperatures - Answers False
Martensite makes a steel - Answers Harder and more brittle
Strain is best described as - Answers A change in length over the original length
Elastic deformation refers to - Answers Non-permeant deformation
When the stress is given as a positive value - Answers The material is under tension
Diffusion is faster in - Answers Lower activation energy, Q, materials
Martensite in steels forms under - Answers Rapid cooling to room temperature from the FCC
austensite phase field
When the temperature lowers in a material, the number of vacancies - Answers Decreases linearly
with temperature
Tempering - Answers Increases the amount of martensite in a steel
Dislocations are the mechanisms that assist in the deformation of a material - Answers True
Which is not a type of dislocation - Answers tilt
Diffusion can occur in a metal when all the atoms are the same type - Answers True
A Schottky defect is - Answers A pair of oppositely charged ion vacancies
Cementite (Fe3C) is - Answers A hard, brittle phase in steels
When the stress is given as a negative values, - Answers The material is under compression
Diffusion is slower in/with - Answers Close-packed structures
In general, interstitial diffusion is slower than substitional diffusion - Answers False
Two fundamental types of dislocation - Answers Edge & Screw
It is possible to produce a perfect crystalline - Answers False
Slow cooling leads to - Answers Equilibrium
Fast cooling leads to - Answers Cored Structure
Diffusion is faster with secondary bonds - Answers True
For technologically important alloys, is a metastable or equilibrium state desired? - Answers
Metastable, more long lasting
0D Defects - Answers Point Defects (vacancies, , interstitials, substitutional)
1D Defects - Answers Line Defects (edge dislocations, screw dislocations)
2D Defects - Answers Planar Defects (grain boundaries, twin boundaries, phase boundaries, stacking
faults)
3D Defects - Answers Volume Defects (inclusions, porosity, voids, cracks)
