Which of the following statements concerning dislocations is FALSE? Dislocation

ID: 485634 • Letter: W

Question

Which of the following statements concerning dislocations is FALSE? Dislocation density (count per volume) generally increases during plastic deformation at room temperature. The energy required to move a dislocation increases as the magnitude of the Burgers associated with a given slip direction increases in a crystal vector Dislocations that are in close proximity tend to mutually prevent one another's motion. Dislocation motion is generally more difficult in BCC metals versus HCP metals. Dislocations move in response to local shear stresses within a crystal. Dislocations feature strain fields that interact with other strain fields in a crystal (such as those produced other crystalline defects). While dislocations can exist in ionic and covalent ceramic materials, their motion in these materials is extremely difficult compared to metals. Dislocations prefer to slip on high density planes and in high density directions within a crystal.

Explanation / Answer

Which of the following statements concerning dislocations is FALSE?

The energy required to move a dislocation increases as the magnitude of the Burger's vector associated with a given slip direction increases in a crystal.----------- FALSE

Dislocation density (count per volume) generally increases during plastic deformation at room temperature.--------------TRUE

Dislocations feature strain fields that interact with other strain fields in a crystal (such as those produced by other crystalline defects). .--------------TRUE

While dislocations can exist in ionic and covalent ceramic materials, their motion in these materials is extremely difficult compared to metals.-TRUE

Dislocations move in response to local shear stresses within a crystal.--TRUE

Dislocations that are in close proximity tend to mutually prevent one another's motion.-FALSE

Dislocation motion is generally more difficult in BCC metals versus HCP metals. -TRUE

Dislocations prefer to slip on high density planes and in high density directions within a crystal. . -TRUE

explanation