Group 4: Dislocations

What is a dislocation?

Dislocations are a type of point defects that have a large impact on the properties of materials. They are a irregularity in a crystal structure that causes a change in the arrangement of atoms in a lattice dislocations are natural defects and have two key properties;

• • · They are defects that cause misalignment in a lattice

  • · They can move across a material

The two main types of dislocations are;

• 1. Edge dislocations – an extra half plane of atoms that centres on a dislocation line

  2. Screw dislocations – a dislocation line that passes through the centre of a spiral

Figure(a) An example of Screw Dislocation