# Dislocation Theory Flashcards

1
Q

Defect type of the dislocations?

A

Dislocations are line defects but they are really loops.

2
Q

Different types of dislocations?

A

Edge and screw are the main types of dislocations.

3
Q

What is mixed dislocations?

A

Many dislocations in crystalline materials have both edge and screw components.

4
Q

What is a slip?

A

The process by which plastic deformation is produced by dislocation motion.

5
Q

What is slip plane?

A

The crystallographic plane along which the dislocation line traverses.

6
Q

What is dislocation density

A

The number of dislocations in a material, is expressed as the total dislocation length per unit volume or, equivalently, the number of dislocations that intersect a unit area of a random section.

7
Q

What is slip system

A

A specific crystallographic plane and direction along which dislocations move most easily within a crystal lattice.

8
Q

What is burgers vector

A

A vector that represents the magnitude and direction of lattice distortion caused by a dislocation. It is perpendicular to the dislocation line.

9
Q

What is twinning?

A

A specific crystallographic plane and direction along which dislocations move most easily within a crystal lattice.

10
Q

How to find Burgers vectors?

A
11
Q

Which burgers circuit has burgers vector? Dislocated crystal or perfect crystal?

A

Both dislocated crystal and perfect crystal have burgers circuit however
Burgers vector can only be happen in perfect crystal lattice. Because otherwise you can not decide it on the dislocated crystal.

12
Q

How to create burgers vector?

A

Count the lines on the dislocated crystal and you will end up with more number when you are coming back to the start point. Count the same way on the perfect crystal and don’t forget to get in where the half plane is happen and after finishing connect the end point with start point. This drawn vector is burger’s vector

12
Q

On which plane do we draw the burgers circuit?

A

Same plane that lattice lay on.

13
Q

A dislocation line cannot end …..

A

A dislocation line cannot end inside the crystal

14
Q

Dislocation line direction perpendicular to the burgers vector

A

Edge dislocation

15
Q

Dislocation line direction parallel to the burgers vector

A

Screw dislocation

16
Q

Dislocation line motion parallel to the burgers vector

A

Edge dislocation

17
Q

Dislocation line motion perpendicular to the burgers vector

A

Screw dislocation

18
Q

Surface step ….. to the the burgers vector both screw and edge dislocatios

A

parallel

19
Q

What motion dislocation loops can not do?

A

They can not do translation. But they can expand or contract.