Dislocation Theory Applied to Thermo-Mechanical Treatments of Metals

The course is given every second year, next time will be autumn 2016.
The course begins with a general description of the sub-structure evolution during plastic deformation of metals.
Thereafter: Dislocation climb and static recovery.Some fundamental theories for deformation hardening, including different stages of hardening and the relevance of dynamic recovery in this connection. Geometrically neccesary dislocations.

After completing the course the student should be able to:

• Derive the equilibrium concentration of vacancies in a metal at equilibrium and locally at a dislocation.
• Derive climb speed of a dislocation with or without equilibrium concentration of vacancies.
• Explain the different models of how the tension related to the microstructure.
• Derive a model for the thermal stress component for the pure metal and metals with alloy elements in solid solution.
• Explain the Cottrell-Stokes law on the effect of instant changes of strain rate and / or temperature from the models for the thermal stress contribution and explain what a Haasen plot shows.
• Outline how dislocation structures are formed by plastic straining.
• Explain what forms the basis of a work hardening theory.
• Derive a one-parameter model for storage and dynamic recovery of dislocations by plastic deformation.
• Discuss the multi-parameter models and the differences between them.
• Be able to explain geometrically stored dislocations.
• Be able to explain how non-shearable particles, equiaxed or disc-shaped, affects storage of dislocations and stage II work hardening.

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