MSE 250 FINAL EXAM QUESTIONS & ANSWERS
Type of bonding in metals - Answer -metallic
Arrangement of metals - Answer -crystalline arrangement (orderly)
Other characteristics of metals - Answer -strong, stiff, ductile, resistant to fracture
High thermal and electrical conductivity
Kind of bonding in ceramics - Answer -ionic
Characteristics of ceramics - Answer -strong stiff BUT brittle
Insulating
Often chemically inert (nonreactive)
Kind of bonding in polymers - Answer -covalent bonding with a carbon chain backbone
Characteristics of polymers - Answer -soft ductile low strength low density
Insulating
Amorphous arrangement (non-orderly)
What five things can a tensile test measure (SSDTH) - Answer -strength stiffness
ductility toughness and hardness
TRUE stress and strain is dependent on what? - Answer -geometry
Stress is represented by what variable and is on which axis of a stress strain curve? -
Answer -sigma and y-axis and in mpa
Strain is represented by what variable and is on which axis of a stress strain curve? -
Answer -cursive e thing and x axis
Elastic deformation is - Answer -reversible
Plastic deformation is - Answer -permanent
FCC characteristics (atoms/cell and coordination #) - Answer -# atoms/cell=4
Coordination #=12
SC (simple cubic) characteristics (atoms/cell and coordination #) - Answer -#
atoms/cell=1
Coordination #=6
BCC characteristics (atoms/cell and coordination #) - Answer -# atoms/cell=2
Coordination #=8
, Substitutional impurity - Answer -usual lattice sites, same size atoms and crystal
structure
Interstitial impurity - Answer -sits between usual lattice sits, atoms must be smaller that
host atoms
Covalent bond difference in electronegativity - Answer -large
Covalent bond does what with its electrons - Answer -shares them
Metallic bond difference in electronegativity - Answer -small
Metallic bond does what with its electrons - Answer -shares them
Ionic bond difference in electronegativity - Answer -large
Ionic bond does what with its electrons - Answer -transfers them
Polymorphism - Answer -having more than one crystal structure
Allotropy - Answer -polymorphism in elements
What three things can you get from phase diagrams - Answer -phases present phase
composition and amounts of each phase
Twinning - Answer -when two lattice orientations are mirror images across their dividing
line
Grain size reduction - Answer -grain boundaries act as obstacles to moving
dislocations (dec in grain size leads to inc in total length of grain boundary)
Solid solution strengthening - Answer -impurities/alloying elements usually induce
compressive/tensive stress because of size differences
Precipitation hardening - Answer -enough impurity atoms concentrate together to form
a second phase particle
Strain hardening - Answer -purposely deform a material to add more dislocations leads
to reduction in movement
Composites characteristics - Answer -combination of two or more classes of materials,
fused at microscopic scale
Young's modulus is a measure of the __________________ of a material - Answer -
stiffness
Type of bonding in metals - Answer -metallic
Arrangement of metals - Answer -crystalline arrangement (orderly)
Other characteristics of metals - Answer -strong, stiff, ductile, resistant to fracture
High thermal and electrical conductivity
Kind of bonding in ceramics - Answer -ionic
Characteristics of ceramics - Answer -strong stiff BUT brittle
Insulating
Often chemically inert (nonreactive)
Kind of bonding in polymers - Answer -covalent bonding with a carbon chain backbone
Characteristics of polymers - Answer -soft ductile low strength low density
Insulating
Amorphous arrangement (non-orderly)
What five things can a tensile test measure (SSDTH) - Answer -strength stiffness
ductility toughness and hardness
TRUE stress and strain is dependent on what? - Answer -geometry
Stress is represented by what variable and is on which axis of a stress strain curve? -
Answer -sigma and y-axis and in mpa
Strain is represented by what variable and is on which axis of a stress strain curve? -
Answer -cursive e thing and x axis
Elastic deformation is - Answer -reversible
Plastic deformation is - Answer -permanent
FCC characteristics (atoms/cell and coordination #) - Answer -# atoms/cell=4
Coordination #=12
SC (simple cubic) characteristics (atoms/cell and coordination #) - Answer -#
atoms/cell=1
Coordination #=6
BCC characteristics (atoms/cell and coordination #) - Answer -# atoms/cell=2
Coordination #=8
, Substitutional impurity - Answer -usual lattice sites, same size atoms and crystal
structure
Interstitial impurity - Answer -sits between usual lattice sits, atoms must be smaller that
host atoms
Covalent bond difference in electronegativity - Answer -large
Covalent bond does what with its electrons - Answer -shares them
Metallic bond difference in electronegativity - Answer -small
Metallic bond does what with its electrons - Answer -shares them
Ionic bond difference in electronegativity - Answer -large
Ionic bond does what with its electrons - Answer -transfers them
Polymorphism - Answer -having more than one crystal structure
Allotropy - Answer -polymorphism in elements
What three things can you get from phase diagrams - Answer -phases present phase
composition and amounts of each phase
Twinning - Answer -when two lattice orientations are mirror images across their dividing
line
Grain size reduction - Answer -grain boundaries act as obstacles to moving
dislocations (dec in grain size leads to inc in total length of grain boundary)
Solid solution strengthening - Answer -impurities/alloying elements usually induce
compressive/tensive stress because of size differences
Precipitation hardening - Answer -enough impurity atoms concentrate together to form
a second phase particle
Strain hardening - Answer -purposely deform a material to add more dislocations leads
to reduction in movement
Composites characteristics - Answer -combination of two or more classes of materials,
fused at microscopic scale
Young's modulus is a measure of the __________________ of a material - Answer -
stiffness
