Slip - ANSWER Produces plastic deformation by dislocation motion.
Slip Planes - ANSWER Crystallographic plane along which the
dislocation line traverses.
Dislocations move along proffered slip planes - ANSWER -Dislocations
do not move with the same degree of ease on all crystallographic plance
and in all crystallographic directions
-There is ordinarily a preffered plane
Slip System - ANSWER Combination of slip plane and direction.
Depends on crystal structure of the metal
minimum - ANSWER The atomic ditortion that accompanies the motion
of a dislocation within the sslip system
slip planes - ANSWER have densest atomic packing
slip directions - ANSWER corresponds to the most closely packed
direction
twinning - ANSWER a shear force can produce atomic displacements
such that atoms on one side of the plane are mirror images to the other
side of the plane
Displacement magnitude within the twin region is - ANSWER
proportional to the distance from the twin plane
Twinning occurs on a - ANSWER definite crystallographic plane and in a
specific direction that depend on crystal structure.
-Occurs in BCC and HCP structures
-Low temps and at high rates of loading
, Slip - ANSWER -crystallographic orientation above and below slip plane
is the same before and after deformation
-slip occurs in distinct atomic spacing
twinning - ANSWER -reorientation across twin plane
-atomic displacement for twinning is less than inter-atomic separation
-Occurs in conditions where slip is restricted
-Amount of bulk plastic deformation is normally small relative to slip
Grain size in a polycrystalline metal influence - ANSWER Avg grain
diameter
- Machine properties
Grain boundaries act as barriers to - ANSWER dislocation motion
Two facts about grain size - ANSWER -since two grains have different
orientations, dislocation passing through must change direction of
motion...becomes more difficult as crystallographic misorientation
increases
-Atomic disorder within a grain boundary will result in a discontinuity of
slip planes from one grain to another
Recovery, Recrystallization, and Grain Growth - ANSWER Properties
and structures formed by cold-working can be removed by heat
treatments at elevated temperatures
Recovery - ANSWER some of the stored internal strain energy is
relieved by dislocation motion, as a result of enhanced atomic diffusion
at elevated temperatures
Recrystallization - ANSWER After recovery is complete, grains are still in
a relatively high energy state. A new set of strain-free and equiaxed
grains forms with low dislocation densities and are characteristic of pre-
cold worked conditions.
New grainse form as very small nuclei and grow until - ANSWER they
completely consume the parent material
Slip Planes - ANSWER Crystallographic plane along which the
dislocation line traverses.
Dislocations move along proffered slip planes - ANSWER -Dislocations
do not move with the same degree of ease on all crystallographic plance
and in all crystallographic directions
-There is ordinarily a preffered plane
Slip System - ANSWER Combination of slip plane and direction.
Depends on crystal structure of the metal
minimum - ANSWER The atomic ditortion that accompanies the motion
of a dislocation within the sslip system
slip planes - ANSWER have densest atomic packing
slip directions - ANSWER corresponds to the most closely packed
direction
twinning - ANSWER a shear force can produce atomic displacements
such that atoms on one side of the plane are mirror images to the other
side of the plane
Displacement magnitude within the twin region is - ANSWER
proportional to the distance from the twin plane
Twinning occurs on a - ANSWER definite crystallographic plane and in a
specific direction that depend on crystal structure.
-Occurs in BCC and HCP structures
-Low temps and at high rates of loading
, Slip - ANSWER -crystallographic orientation above and below slip plane
is the same before and after deformation
-slip occurs in distinct atomic spacing
twinning - ANSWER -reorientation across twin plane
-atomic displacement for twinning is less than inter-atomic separation
-Occurs in conditions where slip is restricted
-Amount of bulk plastic deformation is normally small relative to slip
Grain size in a polycrystalline metal influence - ANSWER Avg grain
diameter
- Machine properties
Grain boundaries act as barriers to - ANSWER dislocation motion
Two facts about grain size - ANSWER -since two grains have different
orientations, dislocation passing through must change direction of
motion...becomes more difficult as crystallographic misorientation
increases
-Atomic disorder within a grain boundary will result in a discontinuity of
slip planes from one grain to another
Recovery, Recrystallization, and Grain Growth - ANSWER Properties
and structures formed by cold-working can be removed by heat
treatments at elevated temperatures
Recovery - ANSWER some of the stored internal strain energy is
relieved by dislocation motion, as a result of enhanced atomic diffusion
at elevated temperatures
Recrystallization - ANSWER After recovery is complete, grains are still in
a relatively high energy state. A new set of strain-free and equiaxed
grains forms with low dislocation densities and are characteristic of pre-
cold worked conditions.
New grainse form as very small nuclei and grow until - ANSWER they
completely consume the parent material
