Dislocations

Learning objectives

The PhD candidate acquires fundamental knowledge on

• the character of dislocations at the atomic scale in different crystal structures
• the different types of dislocations
• the motion of dislocations
• the interaction of dislocations with microstructural features
• the role of dislocations in the mechanical behaviour of metals

Contents

• partial dislocations, superdislocations, dislocation loops
• observation of dislocations
• interaction between dislocations
• formation of cell structures
• motion of dislocations, climb, cross-slip
• multiplication of dislocations
• geometrically necessary dislocations
• recovery
• interaction between dislocations and microstructural features

Required background

The PhD candidate should have basic knowledge on

• the crystallography of metals
• dislocations
• mechanical behaviour of metals
• atomic interaction and defect energies

Course material

D. Hull and D.J. Bacon, Introduction to dislocations,
4th edition, ed. Butterworth & Heinemann, Oxford (1965, 2001)

Introductory chapters
1. Defects in crystals
2. Observation of dislocations
3. Movement of dislocations

Chapters on the character of dislocations
4. Elastic properties of dislocations
5. Dislocations in FCC metals
6. Dislocations in other crystal structures
7. Jogs and the intersection of dislocations

Chapters on the behaviour of dislocations in relation to deformation
8. Origin and multiplication of dislocations
9. Dislocation arrays and crystal boundaries
10. Strength of crystalline solids

The first category of chapters should be more or less trivial to the PhD candidate. The second category is more important, but the focus of the module is on understanding the chapters 8−10.

ECTS credits:
1.5(=5GSC)

Lecturer(s):
Prof.Dr.Ir. Jilt Sietsma

Course dates:
Five weekly 2-3 hour discussion meetings, for which the PhD candidates prepare by reading chapters of the book.

• April 2020: Wednesdays 15, 22 and 29
• May 2020: Wednesdays 6 and 13

Always at 14.00-17.00 hrs
Room: H-3-170

Group sizes:

The course will be offered for a minimum of 4 participants and a maximum of 8 participants per session. Access will be on a first come first served basis.

Assessment:
Take-home assignment to write an essay on a selected topic.

Contact:
PhD candidates wishing to participate should contact Prof.Dr.Ir. Jilt Sietsma by email (J.Sietsma@tudelft.nl) as soon as possible, indicating their primary study, supervisor/promoter and preferred start date.