On completion of this TLP you should:
- Understand why a dislocation forms and how the dislocation width can be determined using an atomistic model, by minimisation of misfit energy due to in-plane stress and misalignment.
- Appreciate how the energy changes as a dislocation moves and how the parameters of atomic spacing, Shear modulus and Poisson ratio affect the total misfit energy.
- Be familiar with the concepts of Peierls stress and lattice resistance and compare theoretical and experimental values. Also understand the difference between the linear elastic analytic solution used by Peierls and the atomistic model.
Before you start
- Look through the TLP on Introduction to Dislocations
- These pages on dislocation width and Peierls Nabarro stress will be particularly useful.
- This LD shows what happens when dislocations interact to cause work hardening. It also covers the formation of dislocations (Frank Read sources).