BME2811 Exam 3 Question and
answers correctly solved 2025
For a given material, would you expect the grain boundary energy to be
greater than, same as, or less than the surface energy? - correct answer Less
than; in grain boundaries some atoms on one side of a boundary will bond to
atoms on the other side but this doesn't happen in surface boundaries. There
will be fewer unsatisfied bonds along a grain boundary and the energy will be
less that a surface energy with more unsatisfied bonds.
Why is grain boundary energy of a large-angle grain boundary greater than
that of a small angle one? - correct answer Large angle grain boundaries have
larger energy because more atoms bond across smaller angle boundaries.
There are more unsatisfied bonds in a large angle grain boundary.
Slip direction - correct answer the direction with which dislocation motion/slip
occurs
Slip plane - correct answer a 2-D plane with which slip can easily occur in the
direction of the plane
Slip system - correct answer a set of symmetrical slip planes
Do all metals have the same slip system? - correct answer No; slip system in
most metals will consist of the most densely packed crystallographic plane
and within that plane, the most closely packed direction. The plane will be
different depending on the crystal structure of the metal.
Why are large-angle boundaries more effective in interfering with the slip
process than small-angle grain boundaries? - correct answer There is more
crystallographic misalignment in the grain boundary region in large-angle
answers correctly solved 2025
For a given material, would you expect the grain boundary energy to be
greater than, same as, or less than the surface energy? - correct answer Less
than; in grain boundaries some atoms on one side of a boundary will bond to
atoms on the other side but this doesn't happen in surface boundaries. There
will be fewer unsatisfied bonds along a grain boundary and the energy will be
less that a surface energy with more unsatisfied bonds.
Why is grain boundary energy of a large-angle grain boundary greater than
that of a small angle one? - correct answer Large angle grain boundaries have
larger energy because more atoms bond across smaller angle boundaries.
There are more unsatisfied bonds in a large angle grain boundary.
Slip direction - correct answer the direction with which dislocation motion/slip
occurs
Slip plane - correct answer a 2-D plane with which slip can easily occur in the
direction of the plane
Slip system - correct answer a set of symmetrical slip planes
Do all metals have the same slip system? - correct answer No; slip system in
most metals will consist of the most densely packed crystallographic plane
and within that plane, the most closely packed direction. The plane will be
different depending on the crystal structure of the metal.
Why are large-angle boundaries more effective in interfering with the slip
process than small-angle grain boundaries? - correct answer There is more
crystallographic misalignment in the grain boundary region in large-angle
