Dislocations and Grain Boundaries

Learning objectives

The learning objective is to master a fundamental understanding of the properties of dislocations and grain boundaries in metals in the following areas:

  1. Dislocation geometry: the geometrical properties of dislocations, the rules governing dislocation reactions and the directions of dislocation motion in response to an applied stress.
  2. Dislocation mechanics: elastic field, line energy and line tension of dislocations and forces on dislocations
  3. Dislocation interactions and applications: interactions between dislocations, arrays of dislocations, strengthening mechanisms, dislocation kinetics, formation of dislocations at interfaces.
  4. Partial and extended dislocations: partial dislocations in FCC metals and superdislocations
  5. Grain boundary geometry: grain boundary orientation variables, coincidence site lattice and displacement shift complete lattice.
  6. Grain boundary mechanics: low-angle tilt and twist boundaries, grain boundary edge and screw dislocations and disconnections

Contents

Dislocations and grain boundaries are defects that largely determine the strength, ductility and other properties of metals. Moreover, dislocations and grain boundaries play an important role in the recrystallization, precipitation and phase transformation kinetics during the processing of metals. Therefore, an in-depth understanding of the properties of metals requires a study of dislocations and grain boundaries: their morphology, formation, interactions and mobility.

Required background

The PhD-student should have basic knowledge on

  • the crystallography of metals
  • dislocations
  • mechanical behaviour of metals

atomic interaction and defect energies

Course material

  1. Imperfections in crystalline solids, Wei Cai and William D. Nix, Cambridge University Press, ISBN 978-1-107-12313-7
  2. Introduction to dislocations, D. Hul land D.J. Bacon, Butterworth Heinemann, ISBN 0-7506-4681-0

ECTS credits:
2 Ects /5 GS

Lecturer(s):
Dr. ir. Erik Offerman

Course dates:
The course dates are the same as for the Master-course ‘MS43200: Metals Science 2’. The course starts on 25 April 2023 at 15:45 in room ME-H. The graduate school course will be part of this master course, but it will be shorter than the master course. If you like to learn more about precipitation and phase transformation kinetics, you are most welcome to join the rest of the master course as well.

Group sizes:
1 – 20 persons

Assessment:
The PhD-students are expected to attend all lectures and actively participate in the discussion. A PhD-student presents one lecture his/her-self. The slides are already prepared.

Contact:
Dr. ir. Erik Offerman