MAAE 2700 EXAM QUESTIONS WELL ANSWERED LATEST UPDATE 2026
Materials Science - Answers - structure
- properties
- performance
- processing
- characterization
Structures - Answers - microstructures (optical microscope)
- atoms (TEM)
- subatomic particles (quantum microscope)
Properties - Answers - mechanical
- electrical
- thermal
- magnetic
- optical
- deteriorative
Metals - Answers - non-local electrons
- good conductivity
- lustrous
Ceramics + Glass - Answers - oxides, nitrides
- insulators
- hard + brittle
Polymers - Answers - organic
- plastic + rubber
- large molecules
- low density + flexible
Composites - Answers a mixture of 2 or more materials
Semi-Conductors - Answers control with insulators + super-conductors
Bio-materials - Answers non reactive + don't dissolve in body
Selecting Materials - Answers - properties
- cost
- availability
- manufacturability
- environmental concerns
Traditional - Answers use "best option" from past designs
Evolutionary - Answers same type w improved characteristics
Revolutionary - Answers new type
Electropositive - Answers gives up electrons
Electronegative - Answers takes electrons
No Order - Answers monoatomic gases
Short-Range Order - Answers mostly liquids
Long-Range Order - Answers crystalline materials (metals and alloys)
Crystalline - Answers repeating atoms w unit cells
Simple Cubic Structure - Answers CN = 6
1 atom/unit cell
rare b/c of low packing density
Body-Centered Cubic Structure - Answers CN = 8
2 atoms/unit cell
Face-Centered Cubic Structure - Answers CN = 12
4 atoms/unit cell
Hexagonal Closed-Packing Structure - Answers 6 atoms/unit cell
ideal e/a ratio = 1.633
Single Crystal - Answers - perfectly repeating atoms
- properties based on direction
- can be made artificially
Anisotropic - Answers directional (larger)
Polycrystals - Answers - common
, - anisotropic or isotropic
- properties may vary w direction
Isotropic - Answers non-directional (smaller)
Polymorphism - Answers different cubic structures exist at different temperatures
Slip - Answers deformation under loading
varies on crystal orientation
Miller Indices of Directions - Answers [a b c]
<family of directions>
lattice parameters = a, b, c
Family of <100> - Answers [100]
[001]
[010]
Miller Indices of Planes - Answers (h k l)
{family of planes}
lattice parameters = h, k, l
if planes and directions have the same set of indices, they are ____________ - Answers perpendicular
Finding Planar Indices - Answers - take axial intercepts
- reciprocate
- simplify
Slip Systems - Answers plane w highest PD
direction w highest LD
- each metal can deform on 1 plane
x-Ray Diffraction - Answers determine crystal structures
Diffraction - Answers series of obstacles that scatters the wave
Defects - Answers disruption of crystalline order
Types of Defects - Answers - point
- linear
- planar
- volume
Point Defects - Answers - atoms get enough E to break bonds + move
- intrinsic = atomic vacancy
- extrinsic = substitution
Vacancies - Answers - missing atom in lattice position
- naturally occurring
- increases entropy
- causes planar disruption as atoms readjust
Self-Interstitial - Answers when an atom occupies a site that distorts surrounding lattice (vacancy +
interstitial)
Solid Solution (Extrinsic) - Answers - alloying (add atomic impurities that evenly distribute)
- solvent = host atoms
- solute = minor concentration
- crystal structure maintained
- homogeneous
Types of Solid Solution - Answers - substitutional = solute + solvent are same size
- interstitial = solute smaller than solvent, so occupies interstitial positions
Hume-Rothery Rules (Substitutional Solid Solution) - Answers conditions for an element to dissolve in
metals
1) atomic radius differ less than 15%
2) similar electronegativities
3) same pure crystal structures
4) max. solubility occurs at same valence
Hume-Rothery Rules (Interstitial Solid Solution) - Answers conditions for an element to dissolve in
metals
1) solute atoms smaller than solvent pores
2) similar electronegativities
3) same valence
4) has max. solubility concentration
Materials Science - Answers - structure
- properties
- performance
- processing
- characterization
Structures - Answers - microstructures (optical microscope)
- atoms (TEM)
- subatomic particles (quantum microscope)
Properties - Answers - mechanical
- electrical
- thermal
- magnetic
- optical
- deteriorative
Metals - Answers - non-local electrons
- good conductivity
- lustrous
Ceramics + Glass - Answers - oxides, nitrides
- insulators
- hard + brittle
Polymers - Answers - organic
- plastic + rubber
- large molecules
- low density + flexible
Composites - Answers a mixture of 2 or more materials
Semi-Conductors - Answers control with insulators + super-conductors
Bio-materials - Answers non reactive + don't dissolve in body
Selecting Materials - Answers - properties
- cost
- availability
- manufacturability
- environmental concerns
Traditional - Answers use "best option" from past designs
Evolutionary - Answers same type w improved characteristics
Revolutionary - Answers new type
Electropositive - Answers gives up electrons
Electronegative - Answers takes electrons
No Order - Answers monoatomic gases
Short-Range Order - Answers mostly liquids
Long-Range Order - Answers crystalline materials (metals and alloys)
Crystalline - Answers repeating atoms w unit cells
Simple Cubic Structure - Answers CN = 6
1 atom/unit cell
rare b/c of low packing density
Body-Centered Cubic Structure - Answers CN = 8
2 atoms/unit cell
Face-Centered Cubic Structure - Answers CN = 12
4 atoms/unit cell
Hexagonal Closed-Packing Structure - Answers 6 atoms/unit cell
ideal e/a ratio = 1.633
Single Crystal - Answers - perfectly repeating atoms
- properties based on direction
- can be made artificially
Anisotropic - Answers directional (larger)
Polycrystals - Answers - common
, - anisotropic or isotropic
- properties may vary w direction
Isotropic - Answers non-directional (smaller)
Polymorphism - Answers different cubic structures exist at different temperatures
Slip - Answers deformation under loading
varies on crystal orientation
Miller Indices of Directions - Answers [a b c]
<family of directions>
lattice parameters = a, b, c
Family of <100> - Answers [100]
[001]
[010]
Miller Indices of Planes - Answers (h k l)
{family of planes}
lattice parameters = h, k, l
if planes and directions have the same set of indices, they are ____________ - Answers perpendicular
Finding Planar Indices - Answers - take axial intercepts
- reciprocate
- simplify
Slip Systems - Answers plane w highest PD
direction w highest LD
- each metal can deform on 1 plane
x-Ray Diffraction - Answers determine crystal structures
Diffraction - Answers series of obstacles that scatters the wave
Defects - Answers disruption of crystalline order
Types of Defects - Answers - point
- linear
- planar
- volume
Point Defects - Answers - atoms get enough E to break bonds + move
- intrinsic = atomic vacancy
- extrinsic = substitution
Vacancies - Answers - missing atom in lattice position
- naturally occurring
- increases entropy
- causes planar disruption as atoms readjust
Self-Interstitial - Answers when an atom occupies a site that distorts surrounding lattice (vacancy +
interstitial)
Solid Solution (Extrinsic) - Answers - alloying (add atomic impurities that evenly distribute)
- solvent = host atoms
- solute = minor concentration
- crystal structure maintained
- homogeneous
Types of Solid Solution - Answers - substitutional = solute + solvent are same size
- interstitial = solute smaller than solvent, so occupies interstitial positions
Hume-Rothery Rules (Substitutional Solid Solution) - Answers conditions for an element to dissolve in
metals
1) atomic radius differ less than 15%
2) similar electronegativities
3) same pure crystal structures
4) max. solubility occurs at same valence
Hume-Rothery Rules (Interstitial Solid Solution) - Answers conditions for an element to dissolve in
metals
1) solute atoms smaller than solvent pores
2) similar electronegativities
3) same valence
4) has max. solubility concentration
